Does BuddyPress do that for me ?

I there,
I'm newbee with Buddy Press and i have some general question before starting a new project.

BP works with a single WP installation, multi site or both ?
Is it possible to force people to create an account before access content ?
Could peoples create and manage pages like in FB ?
Does BP give me the ability to rate members according their activity on the site ?

Thanks for all