I think there needs to be a user role between site admin and normal user. I know my organization (software development) likes to hoard the site admin accounts. If I was a group admin I would want to:
- Have visibility of users that belong to any one of the groups that I belong to.
- Have visibility of projects where one of my groups has at least read access.
- Add and remove users belonging to other groups I can see, to/from a group where I have admin rights. Users I can't see will have to be managed by a site admin.
- Create a project or wiki and set per-group permissions for the groups I'm a member of. Permissions for other groups would have to be managed by a site admin.
- Create new community users and assign them to a group I admin. If I don't want them to gain admin rights to my project, I would need to be an admin of a second group (e.g. "Customers") that has its own access level for the project or wiki.
I think this manages to keep the idea that a group is just a collection of users. A project doesn't need to belong to a group as it did in FB7 - instead, groups are given access rights to a project.
Being a group admin means that I can change the membership of that group.
I can admin a project if a group I belong to has been given admin rights on that project.
I can create a project or wiki if I'm an admin of at least one group, which automatically gets admin rights to the new project/wiki.