A Ban Keeper lets call it, would be extremely bad in my opinion anyways. Because I ban people from my list if they're failing on mechanics too many times, or they allow carries, or if they're dead set on 2 tanking Garrosh 10 man or flex. There might be enough people out there that ban that person for that reason, but that doesn't mean they're not fit to raid, it just means they're not fit to my playstyle. It's nothing against them at all, it's just personal prefference.

Do you exit or log out? If you swap characters alot you will become disconnected from Battle.net. Logging out does not help fix the problem, only restarting WoW.

It works amazingly for me when I need it. If you break it, just right click on the minimap icon and hit join. Then reloadui after that to fix it. Not sure what breaks it but it's not normally an issue.