Regarding 2), I'd like to point out that just because you "leave" Facebook for another social network doesn't mean that you'd delete your Facebook account. In o

Regarding 2), I'd like to point out that just because you "leave" Facebook for another social network doesn't mean that you'd delete your Facebook account. In other words, the decision to use a new social network wouldn't preclude you from still logging in to other services with your FB login.