Youth Group Plugins

Hi

I was going to call this something to do with social networking but it seemed more sensible to talk about what it actually is! A bunch of young people contributing to one blog with separate user names. What I want to know is what plugins I should use please?

Display user names on front page?
Display whether they are logged on?
Gallery plugin for separate galleries according to user name
Last 10 posts
Tags
Discussion software
Review software
Upload videos, images and links to youtube, etc.
Flickr links
Pages styled to relate to the author

Any more ideas please?

Thanks

Rich