Sorry I don't have time to read through this whole thing at this time, but a couple of quick suggestions: have you tried enrolling him in some musical theater group (if that is at all to his liking) or other music group? not sure what it is about these groups but the kids are over the top NICE and inclusive - we did not do this with my son, but I see a lot of kids in my daughter's group who are like him, and well accepted. My son actually had a good connection the other day with one of these older kids in that group, by chance.
Have you considered conventions? video-gaming, sci-fi, anime, whatever your son is interested in. this used to seem 'fringe' to me, but that is my son, a bit on the fringe. he definitely connects with a lot of what is going on at these events. we have gone to a couple and will probably invite a buddy on the next outing. he has a couple of friends that are genuine and reliable, but one of them moved a bit further away, and the other is in another school at this point, so we are looping back through making new friends. He is in h.s. now, and has some good acceptance in his art class, also, thankfully.
