Hey everyone! Well thanks so very much for taking the time to respond to us. My wife and I have been working hard with our little mister all week and it's paying off. The point made about agitation due to having to go potty was a good one - sometimes we realized that he might have to go and was anxious because of it so we took him out. Several times that was definitely the case.
Other times, he's just excited (usually in the morning first thing and after dinner with huge naps in between) and we try and work the energy out. We live in a condo building but we've started to take him to run full-speed in the halls between the two of us and he seems to really enjoy it! We can't believe how fast our little guy is!!
We encourage playtime and gentle little mourning/bites are okay, but when it's too much he gets "ENOUGH" and right to time-out. He's really stopped biting altogether so I think it's working!
Plus the additional interest/reward of training him new tricks keeps him occupied and gives him lots of positive feedback.
It's a long road ahead but so far we're starting to see progress so thanks to everyone for your input!!