1) They have moments challenges where you have to recreate players big games, for instance 50 points by Klay Thompson. These are usually somewhere between 5,000 - 10,000 MT, but unless you are lucky by already having the card they get real expensive. Last year for Chinese New Years you where able to win a Ruby Jeremy Lin, but I think that was the only cards reward.
2) If just tracks stats on the back of the player card, but it is for all games played regardless of mode and the stats clear if you put the card up on the Auction House. There are no rewards for accumulating stats.