If you really have very explicit content like fisting etc then maybe it's not a bad idea to put up a disclaimer page. you could also put a disclaimer on the bottom of your pages as well mentioning about USC2270 for the models on yout site. But make sure you monitor everything closely with an analytics program like for example "google analytics" so you're sure you don't lose all your traffic on the first page
I'm pretty sure hotlinking your pics doesn't make any difference to search engine ranking. But since nobody knows exactly how google works you are never 100% sure.
Hope this helps