Btw, I'd be okay with nationality clubs.
I know I'm in the minority here, but I actually have no problem with "can I join?" posts. Usually when people post them in my clubs they post them with a reason explaining why they should be allowed to join (apparently not realising that it's against the rules to deny anybody and they need no justification). Even when they don't, it's easy enough just to welcome them in and carry on with the conversation. I've never been in a situation where it's halted or derailed the discussion.
They also help with the member lists, which I love . I think the member list, even though it's not hard to become a member of a club, is a great aesthetic touch to set a club apart from just a thread.