My response to this might be somewhat haphazard, I'm writing it as I read it so you'll get my first impressions on this. Im going to be overly critical, since you want critical feedback. that doesn't mean I don't like something, just that Im going to say things that make you think it over and make a design decision when you do.
The Sword
I'm not sure that those should be the only types of swords available to the class, maybe this becomes a describe your own sword (much like describe your own mask for the faceless), let the apocalyptica shine. As for ptions, refined seems a bit odd to me, a sword is messy because the target they hit makes a lot of blood and if they didnt die, then alot of noise. A sharper blade doesn't make the resulting bloodspray any less everywhere. I'm also worried about the +1weird when you have the weapon, that seems a bit... much. In fact it is by far WAY too much.
Edit:: Your sword options are about as powerful as other character's Playbook moves. You might want to either let all of the sword options for the class come from the moves, thus a Sword, Any sword, becomes the only focus of the playbook, or reconsider the emphasis you're putting here.
retractable blade seems like +hidden would be better then +hi tech. There isnt much tech in such an item honestly. You may want to broaden the concept of sword in this case: considering laser swords, scrap metal swords, gunblades (+close reload), and the like. It might make some people happier when they look over it, but I guess... others far less so. +ap on a sword also seems like overkill, I can see a 50cal rifle blowing a hole through that steel plate, but a person with a very sharp sword is still going to have a lot more trouble due to limitations of their own force, the armor will always matter some (though on a 5harm weapon, its already clear that it wont save that npc in serious armor. I do think a wall or tank however would laugh at it, and should.)
I'm not sure I like any of the weakness options. The jealous could neat but it's the clear choice for darn near anyone in the list. People can have things dropped, taken, or lost in AW far too often for the maelstrom to attack them on top of the fact they lost it. And fickle seems to counteract the idea of the class entirely, who'd want to have to make a cool roll to be able to use their weapon, and what the difference between a partial and a hit roll on that?
I think you might consider less magical options here. Think of it psychologically. Why would a person be so devoted to a weapon, do they think they hear it speaking to them? Does it represent their soul? Do they have to take any challenge that comes their way? Do they break down when parted with it? Do they flip out and kill anyone that touches it? Whatever the reaction might be, and there could be many more reactions then this, it needs to A) be able to suggest multiple layers (maybe the blade is magic, maybe there is a demon in the sword, a dead person, maybe they are in the sword, made they're a crazy guy that thinks he's magic with the sword.) and B. fit the type of PERSON that the playbook is designing, because a playbook isnt a character class so much as it represents a type/personality of an individual.
Ideas might be a focus on Honor, Duty, Law, Code, or Frugality (Im looking for a different word, Monk-like, few worldly possessions.). Whatever that choice, I think it might matter more then the blade does in terms of playbook design. The blade / weapon idea seems hedged into well tred territory already with a battlebabe, gunlugger, faceless and the like occupying most of the KILL THEM ALL positions. Unless this is a replacer playbook, I think a focus other then kill it might be more poignant. Although killem classes are certainly acceptable.
Stats
I dont care what you are, if your job is focused around the butchering and maiming of people, you should not have limited HARD options. There is no situation where this class as listed should not be hard focused. Battlebabe is cool, but when they are they tend also not to very good in the seize by force moments already, which makes that cool favoristism (optional) suggest that they do play fair. This class is Sharp focused, which doesn't mesh well to me with physically taking this 5-harm god-sword and cutting into metal encased men with ease.
Special
The Ronin special seems off. If they are forced into an act of sexual barbarism, I seriously doubt rewarding that moment with 1hold you will protect your rapist even if you aren't willing to seems at all functional. In fact, I find the suggestion counterproductive.
The Moves
Cursed Sword
This is not good. Misses already have narrative implications, there is nothing gained by making them take More damage no matter what they miss rolling, it might not be appropriate to the situation and it certainly doesnt add anything to the gameplay. The +1 ongoing applies to everything done while holding the sword in combat, as written, even talking someone out of fighting, or wrestling over an item found on the ground (with one less hand now). This is a buff debuff type of move that feels like it comes from D&D. Moves should suggest narrative, prescriptive/descriptive traits of the concept. Maybe, if you limit the harm perks on the sword itself... Perhaps Oath: When you issue an oath saying that you will kill someone, you gain a +1 ongoing to rolls that result in harm being dealt to them, but a -1 ongoing to do anything that doesn't directly aid your killing of them. If you are defeated, you cannot attempt to kill them again (or somesuch, I'm just throwing a random idea out there that has that aggressive/blacklash narratively) My suggestion seems a bit to much like faceless's revenge to me, but whatever. (narratively anyway)
Peace of Mind
You dont want this. I've tried to do this, it goes badly. People when they roll high know they're immune to that shotgun no matter what, so they do shit they should die doing just cause. It can take the risk out of the situation where you want and need risk. You'll notice that the other spend your hold moves provide entrance into a scene, or slight alteration of behavior, etc. They don't = I win, and they certainly dont plan their combat around whether they hit or missed on the roll at the start of a session. The faceless's enter combat from anywhere move is close to this, and the opposite is fuck this shit / the cool version. If you want something like this, maybe give them a peace of mind box that lets them mark it when harmed to suffer x amount of the harm later (where they also get to unmark it).
Yojimbo
This seems to be the heart of the class really, and Im not sure why its an optional selection. It seems to be one that should be autoselected. Although Im not sure about the -armor result. All other gear and barter will always be more expensive. I would think that this type of class might eschew armor of all varieties anyway, a 1 armor when you have your sword seems more appropriate then some of the other selections. Of course, in a world with guns, your sword isn't going to stop much. I still believe this move needs a bit more polish to stand out though. Or maybe it just needs better support from the other moves / classes options. If you want this to be an option, I'd make it simplier. Even to the point of, when they're fighting to protect someone, that someone gains +1 armor and the PC gains +1harm (not to be stacked with any +harm on the sword options which at this point I think you'd be better off striking off entirely), but if that someone dies then the PC must atone, the PC forfeits their own life, the PC must kill the person(s) responsible no matter the cost.
The +1 forward here, the +1 forwards from the primarily sharp class's often passed read a sitch, the potential +1 forwards from the cursed sword passive can easily either become Redundant completely, or prevent the character from being able to miss ANY ROLL. A +2 is the highest you can safely go before something breaks, and if its ongoing? >_>;
Battlefield Awareness
I strongly dislike this move. Sharp is already one of the strongest traits due to reading literally everything. I dislike the Juggernaut playbook for this very reason, although at least they have to be inside their suit, which they wont always be able to do. If you want to provide a cool sharp move that could assist in conflicts, besides the already substancial benefits from the read a moves, then maybe look to the battlebabes stare as inspiration. When the battle starts let them do something cool (that isnt the stare) using sharp, that reinforces their ability to rock out here. Still no matter how you cut this cake, this is a Hard class, not a sharp one.
Devil in the wastes
Doesnt seem to fit anything you have previously supported with the class, although it could be an interesting AT THE BEGINNING of the session move. Still though the MC's discretion part makes the whole move problematic. What if the only person he wants to roam around and hurt has MC protection? Also, deleting people offscreen is rarely as interesting as providing them with the chance to do it on scene. Still this clashes heavily with the Yojimbo move, Defender and random Murderer, with a 0 or -1 hard? This one needs to be put under review.
Swordmanship
I guess. Not sold for reasons already stated.
Summation
He gets the best harm-rated weapon that the gunlugger can get, has weaknesses that can be ignored (cant draw the sword, its okay, I has a gun too) or overtake the concept (if you must lose your sword to suffer, then it suggests threats of losing your sword often). The moves feel more like stats then narrative personality traits, but you'll get a handle on that easily enough. The ruthless murder machine can amass a HARM rating that it would take the gunlugger / battlebabe perks to do, and that's just the flavored weapon selection, whose baseweapon already starts off as useful. I'm not sure how the guy survives in the wastes with a sword against guns, but there's been nothing so far to represent this move or flavor wise. Sharp implies brain over brawn, which no part of this playbook embraces. I'm worried about a few of the options here, but probably most bothering is that I don't see any the the concepts weakness played up / overcompensated in the moves. If you have a super sword, why doesn't the super sword matter to your moves? Should you really have a super sword?
After considering the entire setup, I think you've made a Battlebabe. Choose your favorite weapon (sword), pick some tags for it (etc). Take Ice Cold, (using violence against those that aren't ready for it, one-sided violence [sword vs gun tactics 101]). Perfect Instincts to benefit from high sharp and the impressive samurai reactions. Merciless for the +1harm to the sword, or the anything they use to break the guy like a kick, lamp, or truck. Move from another playbook Eye on the Door to match peace of mind, or maybe the Faceless's Rasputin for being scary; you could actually take hard rather then ice cold and pick up the gunlugger's NOT TO BE FUCKED WITH or the Devil with a Blade from MaestroD for hot focused cut em up but only with a sword; even the angel's Touched by Death seems strangely appropriate to the struggling yojimbo's story of descent into a post idealized self. End up with moonlighting and when you swear a yojimbo oath, get +1juggling for the Obligation gig: Protect Someone (they're safe/they're gone), and choose Killings and Bodyguarding as the moonlighting options (the downside is the npc is dead, and that might really matter, let the player decide how they atone for or handle that loss; eitherway -reputation -1juggling cause the gigs gone). You could finish with Battlebabe's Impossible Reflexes for the zen-sword fighter or the Dangerous and Sexy for your intense Duelist which also synergies with devil with a blade, or even the Visions of Death move to deliver on the cursed sword / yojimbo / roaming aspect of death qualities of your class (which fits right into touched by death and moonlighting). Honestly Visions of Death seems to be able to do a great deal of what the Ronin wants to do, protect someone or kill them, with potential backlash for failure.
I have another question to pose to you before I stop writing this. What if the PC dies, does the next guy that walk over and pick up his sword have a 5-harm sword? Nothing in these moves lists prevent someone from saying, I seize your sword by force... and then killing them with it. Maybe it isnt a 5harm sword, maybe it's a 3 harm sword that the samruai takes a PRACTICED move to get +1harm when using.
Tips
When building a playbook, consider the TV tropes associated with it as brain-food--assuming of course you choose one that fits with the others in this postapoc age. If you want to make a Ronin that doesnt feel like a Battlebabe, then you should start by figuring out the rolls the ronin plays in the world, what makes him him? Ronin also means wave-man, suggesting that he has no master. Yojimbo might contradicts this, at least as described. If you end up making an entire hack that has completely unique classes, then some of the above statements no longer apply. A samurai hack would have a completely different move list, that being said.
Be careful dropping too many samurai tropes in together. Duelist =/= Yojimbo =/= Kenjutsu Commander =/= Ninja =/= Zen monk. You can push for Sword-guy easy, but a sword (katana or otherwise) doesn't make a person. Figure out who's the playbook supports and push form there. If you want a backlash cursed sword, then the sword's curse should be highly customizable and play a massive role in shaping the person and the playbook moves.