AFAICS there's no way to tell whether a profile is "inherit only" or
whether it's complete enough to be used by an end user. Would it make
sense to have an empty text file called "inherit-only" (for example)
within profiles which aren't usable?

Here's a pretty picture of all the profiles as of whenever I last
synced:

http://dev.gentoo.org/~ciaranm/docs/profile-tree/profile-tree.png

-- 
Ciaran McCreesh : Gentoo Developer (Vim, Fluxbox, Sparc, Mips)
Mail            : ciaranm at gentoo.org
Web             : http://dev.gentoo.org/~ciaranm