Re: BuddyPress and wpMU, some expert advice needed
1) With WPMU and a user account, you can comment on any blog (provided you’re logged in)
2) This is possible… that page is a template file, so you could customize that with whatever you want.
3) If you already have users blogging on WPMU, BuddyPress will detect these user’s blogs (I’m quite sure BP detects them!). BP groups and forums build off of WPMU’s userbase; groups being a BP thing and forums being a BP/bbPress thing. So when you install BP, your users will have to configure their groups and forums from scratch.
4) Not sure on this one. There’s an option in WPMU to disable blog registration, but if you do that I think it will disable blog registration sitewide. This would be a better question for the WPMU forums.
5) BuddyPress does indeed utilize bbPress for forum functionality. The next version of BP will make it easy to integrate with. Right now, it still requires some grunt work.
You say want a forum for each blog? That’s a little overkill… but something like this can be accomplished with groups and a BP plugin (Marius Ooms’ groupblog plugin or Burt Adsit’s BP Community Blog plugin)
6) Yes you can list all blogs on a page using a WPMU function.
Hope that helps!