I think you sound like you're doing a great job.
Personally, though, I think they should definitely learn to be around SOME other dogs before the age of 16 weeks.
NOT a dog park or a place like Petsmart, but maybe a friend's house who has a dog? I'm probably going against what everyone else will say in here, but I don't think it's fair at all to keep a dog cooped up until they've completed all their shots. Rabies sometimes isn't given until 5-6 months old with the little ones. I began socializing Jackson young. I got him at 9 weeks old where he was introduced to my dad's Jack Russell mix, Lily. Then we introduced him to my mom's dog, Carmen. That first day I brought him home he was so scared, etc UNTIL he saw the other dog! It made him sooo happy and right back at home with another dog in the house. Just be smart about where you take him. A dog park is not a good place, etc.
last shots...can i walk him the same day he gets it?
I posted my thoughts here.