yeah, the tweaky or jerky actions sound like using symptoms to me too.
one other thought on the picking is that although he may not have done it prior to the meth days, he may have developed it as a little ocd behavior, after it started while he was using. my guess is that it will go away with time, but if my man is any indication, it is hard to drop. he mostly does it in his sleep so he can't control it.