Living in a state of fight and flight that is so strong as to influence a person's pain level and ability to handle day to day situations isn't normal. That isn't a way a kid should have to live. I have no doubt your son is trying very hard and that he will continue to look for solutions, to me that is all the more reason that he deserves to get some professional help. It sort of seems like in your post you are suggesting that kids who are nice or sweet never need therapy. As you suggested in your beginning post on this thread, the mind and body are deeply connected. For some more vulnerable kids this may be even more true than for others.

Just like anything else in life there are huge variations from one physical therapist to another and from one clinic to another. To say you went to one clinic and now know that physical therapy doesn't work is like saying you at at one restaurant and it wasn't good so you are never eating out again. If the therapist had no familiarity with motor dyspraxia it isn't a surprise that it wasn't a good fit.

What do you see as the downside of giving him the opportunity to talk with a therapist and get some support through getting his scoliosis cast?