Hi. Glad for the update!
Have you taken him to an occupational therapist? They can pinpoint the source of his clumsiness and quantify if he is mearly on the low side of average or way way below average. What worries me is that he has no intrest in challenging himself physically.
As for tthe play it is clear that his internal resources weren't sstrong enough to handle both shows. I wouldn't think Introversion from that particular example...more if I saw a pattern of being energized ny alone time.
Are you scheduled for testing?
Peace
Grinity
