David,
I don't see any reason your application wouldn't "just work" with the CMS plans we have.
Basically each homepage would be a folder. The user who owns the homepage would be given write permission on the folder and could add content items and folders inside that folder.
We could add some prebuilt styles and templates.
Any package I work on will be subsite-enabled, so that each subsite can have a distinct instance of that package.
