Short answer:
Dacron is safe for any bow. I've never seen a bow designed for FF type materials damaged by it, although the string usually gets the blame if a bow fails with a FF string on it.
Dacron stretches a lot--most FF type materials don't. A lot less adjusting of brace height, a more consistent shot.
FF type materials are a lot tougher/more durable than dacron, and don't cut nearly as easy.
FF type materials are much stronger, so you can use fewer strands for a lighter/faster string.
Chad