I also wondered whether Bodhidharma could have been Tocharian. It seems likely to me. Someone who knows more about him could be helpful here.
As for your other question, could the Tocharians be proto-celts, I wondered about that too.
It seems not to be the case. Tocharian and Proto-celtic are closely related sibling languages, not identical. See here: http://www.oxuscom.com/eyawtkat.htm
You believe the desert mummies are the ancestors of the Tocharians. As far as I know, that hasn't been established, though it seems likely.
Ongelo
