Buddypress and Multi-Site Plugin

I’m building a site which I wish to separate the management of MY content blogs (10) vs USER content blogs by using a multi-site plugin to run the USER blog part.

The question I have is can BuddyPress layer over the top of both areas and bring the users together into one social network?

If this isn't possible using a multi-site plugin, then I guess I'll have to create all blogs at root level.

That being the case, can BuddyPress still work if domain mapping is used for user blogs?

Thanks for any help in advance
Paul