Hmm, Wanda being in that group I always see as a sign of her being “rehabilitated”. Not sure she ever needed that, but I think for some less informed readers it might help a bit. Having villains in that group kinda undermines it in this regard
Aside from that, I like the basic idea. In the Buffy and Angel Comics, there was a Watcher’s Council (not to be confused with the insignificant Watcher’s Council for the Slayers), that had the goal to preserve the remaining magic of the world. It consists for example of Illyria, who is rather affiliated with the good guys, as well as D’Hoffryn, the leader of the Vengeance Demons. So here I could imagine a group where the only condition is that you want to preserve the current reality. Most villains have no interest in the universe getting blown apart under their behind. The Enchantress would be a perfect candidate for membership. Dormammu, I’d rather think not. Of course, that’s only for the actual group. Everyone who is capable to do so should be allowed to enter “The Bar with no Doors”. But under the condition that he/she inside commits no acts of violence that go beyond the typical Bar Brawl. So “punching allowed”, but “no powers”