See, as I started reading I thought "but Michael's doing his thingy over there", but then the more I thought about it, the more I realized that "Weird West" is probably closer to vanilla AW than it is to a straight up historical western hack. I'm enthusiastically commenting on his ideas over there, and I'll do the same with this one, as I always loved the Deadlands setting and vibe.
As a quick note, though, I think that you're on the right track by wanting to divorce it from the "metaplot", or hell, even their particular backstory as to where the weird came from. I'd take a cue from the Dark Sol hack (hey, look, Michael again!) where a bit of the AW approach for setting is mixed in: you get a few details and general outlines, and then you're left to fill in as a group. These days, that sort of thing is way more exciting to me than a fully developed history and major NPCs and blahblahblah.