John -
although I'm not personally in your situation, I can feel your pain by reading this post, and I wanted you to know that you're in my prayers.
Here are my thoughts, for what they're worth.
From what I've read in your other posts, you seem like a strong person and I'm confident that you'll continue to be strong. You've been through an amazingly tough medical situation, yet you seem to have a great outlook and a good sense of humor. It also sounded like you have the support of a loving family which is definitely an asset.
I put a lot of faith in surgeons with proven experience who give me a good "gut" feeling. My surgery was much shorter than yours and my AN was a lot smaller, but I was so impressed by my surgeons and their abilities that I'd literally trust them with my life time and time again. So, if you feel like your surgeon was the best choice for the AN surgery and he's done numerous 7/12 jumps, in my opinion, you should trust his advice. Someone once told me that although surgeries are a huge deal for the patient, to experienced surgeons surgeries are just what they do; it's their job. I saw this in my neurosurgeon - very talented, very respected, highly-qualified, very confident of his abilities - and I knew after meeting him he was one of the guys I wanted at the other end of the scalpel. If you have a good feeling about your surgeon, I think that's a plus.
I wish I could offer suggestions for questions you could ask your surgeon, but I don't know enough about nerves, nerve damage, or the surgery to come up with anything that would be helpful to you. I don't know how open doctors are to this, but since he's done numerous 7/12 surgeries, maybe he has some patients who would be willing to talk to you about their experience. It might not hurt to ask.