This is very much like my DS7--he has what I have always described as a lack of kinesthesia. He does not seem to have a connection in his brain that tells his body how to imitate a pose that is right in front of his eyes. You can hold your hand in a certain way, tell him "do this", and his muscles will work so hard at doing something completely different that you can't even move his hand into the right position to show him! It was only this year that he learned to tie his shoes, and he still cannot ride a bicycle, yet he is DYS, grade-skipped, accelerated to 3 years higher math and bored out of his skull.
I don't know if the lack of kinesthesia is related to DS7's Asperger's or a totally different issue, but from some of your description I would say it wouldn't hurt to look into that in your search for an answer.
