does CustomPress allow admin-defined categories exclusive to admin?

Just want to check my understanding of what CustomPress offers: if I network activate it, will it allow me to define categories to which only I, as superadmin (or admin of sites within my network), have access? By making the taxonomy public or non-public.

I want users to be able to join and register their own blogs (via Multi-Domains) on, for example, SiteA but NOT to be able to assign certain categories eg ‘SiteA Magazines’ to their content.

Could I then somehow assign this category ‘SiteA Magazines’ to the Settings of admin-created subsites of SiteA; and assign a custom menu on the SiteA homepage which displays only admin-created subsites which have the category ‘SiteA Magazines’.

Is this the best way to have top-level (i.e. admin-created) subsites delineated from user-created subsites? I intend to use BuddyPress as widely as possible across the admin-created sites and subsites, but I do not want users to be able to create Buddypress enabled sites.