My dog knows the basic obedience commands but still runs away. What should I do?

I think I have a "problem" dog. He is a 14 month old purebred beagle that was bred as a hunter. I got him when he was 8 weeks old and for the most part, he has been pretty good. Except, he has a nose that won't quit and that leads to more problems. He wont listen when called, pulls on his leash until he is choking, and will run away if let off his leash. He seems to be very protective also, almost vicious. Any advice? I have taught him basic commands which he follows most of the time.

Andrew & Cosmo