ball at rest moved by another ball

Ok I've looked at the rules, but still a little confused. 1....If player A's ball is on the green & player B's ball hits the ball at rest does player B get a 2 shot penalty (presuming both balls were on the putting surface at the start of player B's stroke? 2....If player A then plays on from new postion (not replacing his ball ) does he then recieve a 2 stroke penalty also? 3.... I think i got this bit right, If either or both balls are off the green player B does not get any penalty....but if player A does not play his ball from were it was origionally he would still get a 2 shot penalty?

Pretty much got that spot on mate.