[AbreuTime]

1) Don't fold. Not deep enough to consider it.
2) I check flop. He rarely has a hand like AQ (that would stack off when you cbet); most likely has a pocket pair. You get stacked by AA, QQ, and most other hands fold if you bet flop. To get value from worse hands, and due to the fact that you have only 1.5x PSB left, you can check flop and still stack worse hands.
3) He openraised to 6x bb UTG+1 in full ring. Um, his range for calling the 3bet is pretty snug. And a check is the only way to get value from worse hands. I think a push is -EV (Edit: unless you have a maniac image).