The whole "free site" idea was very confusing to me when I started. Coming from mainstream, I assumed when people said "freesite" they simply meant a porn site that is free, i.e. not a paysite. I later learned that adult webmasters classify their sites as LL's, TGP, fake TGP, blogs and if they can't find any other name for it, they call it a hub
When they use the term "free site" or "freesite" they have something other than simple "not a paysite" in mind - they are thinking about a very speicifc form of mini-site, not necessarily on the root of a domain, with only four pages to it and very structured.
From what I can see in your site (some pages 404), this is a hub/fake TGP combo, where you basically send people to FHG's. Try avoiding calling this a free site when you talk to adult webmasters, as they will be confused.
With this kind of fake TGP, you can certainly mix and match sponsors. All you're doing is sending people out to their FHG's, so you're not using any one sponsor's content to promote another. Greenguy has a great page here with stats about his best converting sponsors, look it up and you get a great list of sponsors to use. A warning page is optional - search this board for the term "warning page" and you should come up with some interesting discussions about their pros and cons.