I love groups, but I don't want to leave any! I just wish I could join as many as I wanted, or 100, or something. As it is, I can ask for invites to groups and sort of get in the back door, but it's a bit of a pain. I don't really understand why there is a limit, either.
As far as chatting in game goes, maybe we could have a way to delete some of them off the in-game chat list, if we are only in the group for the discussions and don't need to have the chat open, if that is the limiting factor here.