For the turn, don't half pot. It's too easily callable for a flush draw and too easily raised if villain reads you for a semibluff. It's hard to learn anying from villains reaction to your bet.

Remember the only 3 reasons for betting: Protect, value, bluff.
I can see betting for protection here against a 4 flush, but what if you are betting into a made flush? I'd give it 50/50 that he's minraising with a made hand. I can't justify betting for value or protection in that case. So check/call small bets and check/fold large, in general. It will take reads on the player to know bet size tendencies on made hands.