1. Bet fold flop if you dont want to get it all in vs possible overpair (in which case you could have shoved pre) as played fold.

2. Call but with 678 and 2 suited cards or 789 & 2 suited is usually the flop that hits the pre-flop raise callers really hard, made straights and big combo draws.
Probably flipping vs his range.

3. Check Behind

4. Call - Even a donk with a set of aces cant not bet that flop with 2 callers, & not a 19/8/2.33
The only thing he's repping on the turn is a set of 4's & those odds are so small (considering he raises 8% tot and its UTG) that I will pay him off.