Flop check is totally fine. 56-QJ, 66-77 are very likely to call you, maybe even underpairs, and a draw could even check-raise you out of the hand when you still have some equity.
Turn is fine... I don't get what he's doing on the river, but I'd just give him credit for being an idiot and slowplaying the flop in position.

Well played imo.

Only thing I don't like - I think you should be opening for 4x, especially UTG, you can go to 3x somewhere between CO and button - although not necessarily.
Every bet you add on any street exponentially increases the amount you can bet on later streets... and when people stack off with tpnk, you want to be able to play for stacks pretty much every hand.
Opening for 3x 100bb deep is good when you want to have more room to maneuver post-flop to outplay your opponents... I'd rather just bet as much as i can get away with though.