1.) YOU HAVE TO BE VERY CAREFUL WHEN CHOOSING THE EXP INCENTIVES.
I have seen Dungeon worlds and Apocalypse worlds in play, and run both of them. Whatever you choose for exp will dramatically effect the way the players strive to behave. For example, if you take on the DW world exp on a miss, then your characters that do awesome things and succeed, will not get the cool stuff. Therefore, the players will try to do what their character sucks at more often in an attempt to wrangle up some additional exp. THIS IS NOT A HEALTHY DYNAMIC.
It works for some playergroups, but I've yet to see it work as smoothly as Highlighting behavior. You see there is something fundamentally different in the setups. DW awards failure. AW awards players acting in ways that appeal to the other players and you. Generally speaking, the highlighting is ALWAYS a better route to take. DW does help mitigate this slightly with the end of session end, did you fulfill your drive/alignment? Did you do find or see something crazy awesome? Did you dig up some sweet treasure? Did you advance your story between at least one other character in a significant way?
Honestly, the only truly useful aspect of DW in comparison to AW is the end of session. The exp on a miss is only a good go-between when you're playing a 1-player game, and even then it feels stifling in my experience. As a player you want to level up, it shouldn't be held against the cool stuff you want to succeed in doing. This stands directly against AW principals of being a fan of a player characters. Missing should be FUN (make it fun), Hitting should be rewarded (being awesome). In AW, it doesn't matter if you hit or miss, just that you DID something (highlighted). Which is a much healthier choice. AW also inspires team-building, it means you care who has the highest Hx with you. It means the MC can effect the character's narrative with incentives. You have to be careful anytime you take that away.
If you want to stray from the EXP workings within AW, then trash BOTH. Give your players a list of things they can do each session to gain exp. Make sure those things inspire individuality, and are healthy/realistic things for a character/story/worldsetting. Incentives help players choose goals. Generally though, I feel that highlighting is a group activity that is good for the dynamic of the game-play. You shouldn't worry too much about EXP getting out of whack between characters, so long as they have
agency in creating that rate. Even if it does, it's not that big of a deal.
The move substitutions actually hurt a player in DW, so you should consider that in your decision, and consider it carefully. In AW, they are in fact a huge perk, which is the point. Now, if you're still worried about move substitutions because of everyone always succeeding a move,
remember: it's your job to make the character's life interesting, not easy. They will miss eventually, even with a +3 to everything, also partial hits should feel like partial hits. For example: Make them want every choice out of a seize by force, every-time, so they're always compromising something. On open your brain... well, sometimes what they SEE they might've wished they hadn't, or maybe the partial is vague enough that it could mean one of multiple things immediately... and only one is true. Vagueness can be maddening. "As you open your brain in the ruins, you suddenly FEEL aggression and hatred hitting you like daggers. Someone here wishes you harm, but who? Someone standing next to you? Or something further away?" TENSION, Escalation and Snowballing.
If your combats have too many opportunities for hard/cool rolls, then zoom back the camera. Instead of rolling seize by force to take down /that/ gunman in a room of baddies, have them seize by force to take the entire building. I'm sure the fights with the peons along the way will have harm-exchanges, but they cant all be important. Also, its okay if there are a few more hard or cool rolls then otherwise, they tend to carry bigger risks for failure. You lose friends, gang members (these don't just regenerate), put your holding at risk, damage or lose shit that wish you hadn't, etc.
AW stories are designed to run at a faster pace then DW. AW games will have stories start and resolve constantly, and in general I've found a game of decent length to resolve themselves at about 6-10 sessions. Sometimes they're longer, but, due to the fact they are as quick as they are, letting people level up often is good. If you want to extend the game... then say every time they "rank up" they need 1 more exp to level. 5 then 6 then 7 then 8 then 9, etc. That will make the game SIGNIFICANTLY longer. I've never had character's get more then 1 "level" apart this way.
2.) If your players aren't using aid/interfere, then that's just odd. If three guys rush into a building with their guns blazing trying to seize the place by force. They all don't need to roll a seize by force, let the biggest baddest do that, the other two roll to aid him in the task. Sure only one +1 forward counts, but if one fails the other is there is back them up. Make sure you ask them HOW they intend to aid the target do this before letting ANYONE roll. To do it they must do it, and all that.
If say... you have the gun lugger hit on a 9, the savvyhead aid with a 6, and the angel aid on a 13. Then the +1 forward is the only reason the gun-lugger managed to seize the building as well as he did. All three of them were laying out body counts, so perhaps more got captured or killed that mightve been able to flee from just the gunlugger. Maybe those that fled, fled with a captive savvyhead, and the angel somehow never even got shot. So exchange harm between the gang in the building and the gunlugger+savvyhead, and narrate the next snowball. Now, say the angel was ALSO trying to disarm a bomb inside of someone in the building and must act under fire to do so. Maybe the gunlugger has experience with bombs and is giving advice, let him aid another. Of course, if he rolls too low, then trouble from the bomb or people running around the building crops up and puts him at risk. etc.
Another ex: If a gunlugger is trying to throw another characters friend off a cliff, and they want to stop him. NOT ONLY can they also roll a act under fire to grab the guy as he falls, but maybe also, they'll interfere with the gunluggers roll to seize the guy to begin with. Whenever one character gets in another's way, they are interfering. Whenever one character backs up another character in something risky (a roll), they're aiding them.
What I'm getting at is.... If your players aren't using these moves, then they must not interact in ways that help or oppose each other. Because it should be very hard not to.
Anyway, I'd like to make the help/interfere move more appealing to use, either by cutting down the risks or improving it's effect, but I don't want to make it over powered. Does anyone have any suggestions? Would simply increasing the effect by 1 point (i.e. +2 for helping, -3 for interfering) work without going too far, do you think? Or maybe an extra point if they get a full hit, normal effect on a partial, but no risk from a partial?
Yes a -3 and a +2 is too much. You need to make the RISK they're taking to aid or interfere with the other action CLEAR and POTENT. If the risk is someone will be annoyed, that's not really a risk. Create the risk if you have too, but keep in mind, people should only be rolling dice when you're not sure what the result would be. A guy tied to a chair doesn't need to have a seize by force rolled against him to put a bullet between his eyes, after-all. SO when anyone is making a roll, it is assumed there is a RISK, tell them what it is, if people can help and they can tell you how they do it, then tell them what the risks for doing so are. That way a 10+ says, I AVOIDED THE GUARDS, AND HELPED YOU BREAK IN! FUCK YES. And a partial is... Well I helped you break in.... NOW IM RUNNING FROM THE GUARDS, OH SHIT. and a miss is just, THE GUARDS! (maybe the guards saw both of them? Maybe just the one, look to the other's roll to find out.)