As for the contact with the shooter's hand after the shot is released, I've got nothing. Fred Flintstone is the only person I've ever seen effect the path of a ball once it's released using further body motion.
As for B1 hittings A1's hand and causing the ball to go OOB, I have to agree with JR that by strict interpretation it would have to be B's ball. But I take the position that the rules committee didn't intend to give B1 free shots at A1's hand, but rather to simplify what would otherwise be a very hair-splitting judgement call by absolving B1 of responsibility for the contact on the hand as long as he is attempting to play the ball. In that case, I think we should proceed as if he did play the ball and give it back to A. The rule may not say that the hand is part of the ball, but I think that's closer to the committee's intent than the strict interpretation.
[Edited by Back In The Saddle on Jul 15th, 2005 at 09:10 PM]