The most fun I've had on the player-facing end of RPGs has very rarely been in combat; it's almost always in the exploration and verbal conflict resolution. I've also always loved fiction and games about scrappy little folk digging around in the (literal or metaphorical) ruins of fantastical civilizations (The Last Unicorn, The Hobbit, Perdido Street Station, Mega Man Legends, The Legend of Zelda: The Wind Waker, Nausicaa of the Valley of Wind, Castle in the Sky, Ico, Dark Souls, Star Wars: The Force Awakens). Apocalypse World and Dungeon World already deal with these themes, to a degree, but I'm thinking of writing a game that puts exploration and puzzle based basic and MC moves at the forefront, pushing violence and PvP conflicts of interest to the wayside. My goal would be, in play, to recapture some of the aesthetic experience of reading the part in The Hobbit where Bilbo emerges from the forest canopy and sees the butterflies above Mirkwood, or in The Wind Waker when you see the entirety of old Hyrule on the ocean floor.

The default mode of play would be scraping out a living by delving into (here largely uninhabited to cultivate a sense of relative desolation) for valuable scraps while facts about the characters relationships (and the death of the old world) emerge organically.

(For even more isolated play, I've been brainstorming a Murderous Ghosts hack inspired by Shadow of the Colossus and Dark Souls)

As the rulebook says, getting your head cut off or being crushed by a boulder isn't damage, it's dying. Bloody Aegis doesn't let you "break" the fiction any more than anything else in the game does.

More importantly, it would be nice to not have our monsters flagged as being house-ruled just because we corrected their damage die sizes.

As a hard-and-fast rule, if the fiction calls for something, it happens. That's how Dungeon World works. Sometimes that fiction triggers a move, and that's when the rules come into play. So yes, Hirelings could be killed by taking the brunt of an effect, in a fight with another NPC, or due to any number of mishaps.

With "use up their resources" as a GM move, I don't think letting players keep their use-generated gear is necessarily disastrous. I'm not sure how it works with load, though.

Sorry to be "that guy," but my version of InDesign is too old to edit it myself. Is there a version of the character sheets where the Cleric has 8+Constitution HP?

There has to be a good reason that the character can't, but remember that even in D20 if a player says "I turn myself inside out and hide inside of my own internal lining!" or some such thing, you should just tell them that they can't, so this isn't a unique thing to Dungeon World. What is unique to Dungeon World is that, when a player wants to do something that doesn't make sense or shouldn't be possible, you should usually use the "Tell them the requirements or consequences and then ask" move.

"You want to kick down that door? You probably could, but it would make a loud noise, and it will be too damaged to lock again . . ." The Fighter has a move that lets them control the circumstances of breaking down doors and such, so that they can avoid unfortunate outcomes like that.

For stealing something, if nobody is watching and the object is something the character can carry, of course they can steal it! If they need to take it without being noticed, they're actually triggering the Defy Danger move, where the danger is being noticed.