Unusual Ferret War Dance, or Fear?

Usually, they do stay out in the open, or if they hop backwards, they bounce forward again. The fact that after he hides probably means that he is still slightly nervous about his surroundings. It's not you, and you should continue to play the same. Just realize that he's three and new to your home, and before long he'll be dooking and dancing everywhere. Good luck and hope this helps!