I’m going to level with you. I don’t think introducing yourself that way on the WoW forums let alone the Argent Dawn ones is going to end in anything positive. Not your fault at all, of course.
I don’t know if there are specifically M+ guilds persay, usually the whole mythic keystone thing is a means to an end for players to get better gear for raiding. That being said, I can’t imagine most people would object to having a consistent person to do M+s with.
As for you being an aspie, I think a lot of guilds would be willing to accept and try to understand you, especially since you’re so open about it. Granted this is a perspective I’ve gotten primarily through RP guilds, but I can’t imagine most PvE guilds lack maturity that badly.
Not really, at this point. The m+ end of dungeon gear is laughably bad now, and the main reasons to push m+ are the keystone master mount and flexing your raider.io score. It’s its own path of endgame progression more or less.