Multiuser blog capabilities

I’m creating a blog/site for unofficial stuff in my small town. I want to give groups in town the capability to use the site. For example I might create a Boy Scouts category.

What I’d like is the ability to assign a user to be the “Author” for that category. A category author could post to that category without moderation, but could not post to other categories (at least not without moderation).

I might also want to have a checkbox as to whether the post appears on the site’s home page or not. This isn’t mandatory; I don’t think there would be too many posts for the home page, but I’m thinking ahead.

Possible?