I have a socially awkward - appear disinterested - introverted boy.
He still have to bonk him in the foot to get him to say hello (and then it's like a low mutter) sometimes - and he's now in junior high.
He just doesn't *get* some social dynamics. So we've coached him, modeled it, but we've had to accept him the way he is.
I too had concerns. Talked to teacher. Then doctor. She met with him separately. She didn't feel there was enough signs there to indicate a condition or disorder. She'd known him for years and felt it was his personality and temperament.
My son had some anxiety concerns and I was a bit worried he wasn't handling social relationships very well in some cases, so we just met with a child psychologist - just to see if she could help.
We met with her for an hour. Then on another day she met with my son.
She didn't feel he had enough signs to fit a diagnosis. Asperger's is a spectrum disorder. So there's a wide range. So some people may have a few symptoms and life can be a little bit awkward for them - but they can get help with some tips and modeling.
So that's what we've done. For us though the biggest thing was finding him a social setting where he just naturally fit in better. For us that was scouting. He met buds that all just accepted him for who he is. They all have their own interests.
He's figured out how to fit in now and has true friends (matured), but he still is very introverted. Likes one on one time. He still makes up stories (like yours). Now he's writing them out into books. So he has an outlet.
Mine has gotten into sports in the last few years. That's been good for him. I wouldn't say it comes naturally to him, but he's so dedicated and learned his position so well, he's actually done well. It's a camaraderie he enjoys.
I read your SWH and I think you're taking the right steps. I think if you meet with the psychologist you'll feel a lot better :)