As previously said it is an ooc character, so you may "play" some with your Knights, or have a talk about the weather or what you gonna have for dinner (in real) and no one will care. In my view thats more a favor because many Newbies having questions concerning the game might be frightend asking questions about the game itself when always being "pointed back" to their Knight and all that role-play stuff.
RP is on board, tavern for talk (even if you have all your friends in msn you might find new ones^^).
On german server we do also have an IRC-Chat you may directly connect over your Ritterheere account, no idea we don't have this option in KH as well.
EDIT: We also had the idea of a national tavern on german server when first Nations started to grow over 70 - 80 Knights, but I have forgotten why that idea was dropped