For the friends system, that's quite interesting idea, just make it that way that people wouldn't "abuse" it and get 200 friends in to their list a day, a limit of something like 30 people perhaps?
It's just so annoying how I get friend requests every frikkin' moment on YouTube and because I'm a lazy person, I always "accept" them, because the people who tried to become "friends" with me might get annoyed or rather pissed off.
Well, the heck I'm complaining here?
It would be the community to decide how to use it, I would keep my list quite short and clean.