WordPress MU

Hi Everyone,
I'm working on a project that will make a lot of information available online - more than I want to organize with tags and categories. My plan is to use a single WPMU system to implement a few sites. The site layout will be similar to the following lame diagram - domain names changed of course...

Recipes.com
|
|--SteakRecipes.com
|
|--ChickenRecipes.com
|
|--SeafoodRecipes.com
    |
    |--FishRecipes.com
    |--ShrimpRecipes.com
    |--OysterRecipes.com

I guess I'm wondering if WPMU is the right tool for this job. More details about what I want to do:
In the above diagram, all posts on Fish, Shrimp and Oyster sites should also be published on Seafood site. In addition, all posts from all sites should be published on Recipes.com, but authors on the Shrimp site shouldn't necessarily be an author on any other site, but all sites should share the same user info.
Does any of that make sense? If not, I'm happy to explain further.
Can anyone let me know if MU will work for this, and if not, point me in the direction of something that might?
Thanks,
James

Yes it can work.

Just aggregate posts from subsites to the parent site.

ie. install feedwordpress on seafoodrecipes then aggregate the posts from fishrecipes, shrimprecipes and oysterrecipes

Similar for the others

I'm guessing that feedwordpress is a plugin. Thanks so much. :-)

Install and play with these two plugins:

Donncha's Sitewide Tags

&

WPMU Enterprise