Being with his family now should also help with his behavior a little bit. He is a big boy!!! Sooooo adorable though! One of my boys is 13.5lbs so I have a teapot too! More to love!
Yorkies (or any dog for that matter) are VERY expensive in the first year, neuter, chipped, vaccinations and now dental work, that is all pretty common things that most dogs actually need. Thankfully he does not have LP, liver shunt or Trachea issues... imagine how much that would be! YIKES!
Sounds like you got a good healthy boy there... take him for training or get books on how to train him. Break him of the aggressive behavior as soon as you can.
Good Luck and happy holidays with your baby!