My son is coming up on 2 years post-TJ next week.
Moving the nerve causes weird feelings in just about every patient. What kind of weird varies. My son had numbness in several fingers at the beginning, which eventually reduced to just weakness, which eventually went away. Also had a few numb/tingly spots on his arm and hand that eventually went away.
The difficulty in fully bending is likely due to residual inflammation from the surgery, which is part of the normal healing process from having your body cut up with a scalpel. Bending the elbow causes tissue compression on the front/inside and extension on the back/outside, either of which can aggravate areas where there is still some inflammation.
My son also got his graft from the gracilis tendon in his leg. It's much larger and stronger than the palmaris longus tendon. We were told by the doctor WTTE "he ain't ever tearing that one." The main trade-off is that you have to rehab two limbs instead of one.
So to sum up, his physical recovery seems normal to me.
As YoungGun stated above, the mental side of this is much tougher than the physical. I don't mean to alarm you, but you should really monitor his mental state throughout his recovery and return to play. The grind of rehab and recovery, inability to play, not being a contributing part of the team, and fears about whether he would ever be able to pitch the same way again all contributed to my son spiraling into anxiety and depression. (In hind sight, he had other indicators prior to surgery, but the injury/surgery/recovery was definitely the tipping point for him.)