I like sign-up forms that give an overview of your involvement in the fandom/interest. So a general "favourite character/favourite episode/how did you get involved in [reason for club]" and so on. Name is okay by me so long as it's more "what should we call you" rather than "username". I usually leave out the username part if it's asked for in clubs. o_O But at least answering well thought-out (but not too complex) questions about the topic in a sign-up form gets people saying something that can be replied to, which is a nice basis for further discussion.
But also agreeing that without the forms, people have a greater tendency to just post with mere "can I join?" intros. I find that ditching user lists also stops this post but people seem to love lists (even though I hate them and find them very tacky and annoying to update--which is why people don't keep them very up-to-date) so I don't bring this up much, lol.
Btw, I'd be okay with nationality clubs.