President_DonaldDuck #2 My guess without checking my answer is Rxd6 because right now if Qxc6then white plays Qxd4 and black cannot retake because it would hang his queen. So Rxd6 threatening the bishop on c6 and the fork on f2.
DVRazoredited #3Doesn't look that good to me. You're giving up two pieces and a rook for a queen and two pawns. (23. Ba4 should be the move)