Sashmom, I would consider taking him to a well recommended groomer and remove the conflict for you entirely until he is more accustomed to being handled. When I got Nina (ANNOUNCEMENT - I GOT HER AT 7) she was very bitey when handled. She got her nails trimmed at the vet, then I called all local vet offices asking for groomer recommendations for a big, black GSD who was not socialized and all gave the same name.
This groomer is awesome, I got to stay (which sometimes makes them worse but she was okay with it) and she had no problems grooming her (she's amazing). Nina eventually ended up loving going there, whining and pulling to get in, and when she got sick and needed handling I was able to do it easily, though I always had the vets or groomer do her nails because I wanted to keep our relationship happy.
She always got people food, from pretzels when I was taking care of her pyoderma, to cheeseburgers (just meat and cheese) after her grooming. Nothing from the bad list. No onion and chocolate sandwiches.
