I am trying to design a specific type of site and would like someone to point me in the right direction.

• main home page with list of public subsites (categories i think). Also a form to become a admin of new category/subsite
• Super admin accepts new pending category admins
• category admins accepts new pending users to allow them to view his posts
• nice front end for cat-admin for creating new posts (not so wordpressy)
• Users could log in from the home page and then redirect to category he registered for but not other categories

So i have looked into wordpress multi-site but it says there in the documentation

if all you want is for different groups of users to have access to different information, then you can probably achieve what you want in a single site by using a plugin to switch capabilities, menus, and link URLs.

I have tried nearly a dozen plugins but they dont seem to have the functionality i want