Diamonte, it sounds like you have been given a handful of horse. I don't mean to offend, but I think the first decision I would be making is whether to give him back to my uncle, or if I thought he was worth the time and effort to train and I liked his personality, then I'd have the vet out to geld him asap.
I don't know from your profile if you've had lots of experience with horses or not. His biting, pushing, rearing and turning his rump to you (e.g. ready to kick) are all very agressive signs that he intends to be the #1. None of those behaviors are acceptable. It sounds like he hasn't been handled very much and hasn't learned his manners. This is a safety issue for you and anyone else who would come in contact with him.
You will get lots of responses from other posters who are much better than me, and much more experienced than me, in handling this kind of problem horse, so I'll be interested in what they have to say. My caution for you, until you get some better advice from the others on this forum, is to be very, very careful. You have to watch out for your safety and this guy is behaving as if he has no respect for you and if he decides to treat you like another horse, to teach you YOUR manners, you will be hurt. Be safe, and good luck!