Annie B was a breeder at a puppy mill for the first 5 yrs of her life. She came to me with a lot of issues. Although a very loving girl she was never one to be hugged. She enjoyed being petted, tummy rubs were the bomb! She'd be happy to sit in my lap, but not so much for cuddling. Boo was a rescue that we got when he was 4. He has loud noise and sudden movement issues. He loves to be petted, to be held, to sit in your lap, but hugs he begrudgingly allows. I feel that they just have such a skewed perspective of life because of their start. I know that's not the case with your boy, in that you've had him since he was young. But he was removed from his litter too soon and a lot of what he would have learned from them, he didn't. So this is just who he is.
Try to not reach for him from above. I'd often just stop and squat down, they'd be curious about my 'odd' behavior and come over to see what I was doing. At first, when they came up to me, I'd just talk to them. If I had a treat, I'd leave it when I stood up to walk on. Then I moved to handing them the treat before standing up. Then to a scratch under the chin followed by the treat. It got to the point were I could reach down to give them the treat without them moving back. I was then able to reach down and give them a pet and move on. But always it was them that approached me. If I was sitting or laying down, they were never as nervous about me reaching out for them. It's good when they learn that you aren't going to pick them up every time you reach for them. That sometimes you just are going to give a little pet and then move on. Watch for the funny look on his face when that's all you do and then walk away. He'll be like, "Huh? What? Hey, wonder why she didn't pick me up?"
I think a lot of what you are seeing with Wookie (love the name, by the way!!) is simply his personality. He may never be the social butterfly you want him to be, so you need to find things to do that fit into his idea of fun. Annie never did enjoy socializing with other dogs, but
loved to go places, see things, meet people...as long as it was in my arms. Annie was the original Queen Diva...and they simply do not
walk anywhere - they are carried by their servant.
So even though it seems he's not interacting with other dogs, if it's not upsetting him I'd still get him out and among the brethren as much as possible. He may actually be enjoying the time with them, in his own way.