QTo vs aggressive 3better on flushdraw board

I think if you're going to 4bet here, it needs to be a bit larger because you are 250bb's deep, and villain may call with a wider range than normal. I think that this is just a fold preflop. OTR, i think it's just a fold because i dont think he will be bluffing often enough with his sizing.

How about cbetting on flop?

Thanks for Your insights. I agree that these cards can not be best for 4bet bluffing, still he was 3betting all day long, so I had to make a move.
His sizing on the river is smaller than half pot - so what does it tells me? If he raises larger, than it is bluff, or vice versa: he raises smaller, lets say - 3$ - then it is bluff? Kevin, can You please explain?

Nitrol - I do not cbet on the flop because I am very vulnerable against reraise. He can drop me off the pot with large reraise - to get me off flushdraw.
I have weak flushdraw here and also straight draw - a possibility he will not see it, I I catch a J. With his call for my 4bet - his range is very strong - so he can have King in his hand in many cases.

What i meant was that the size he used, which is less than half pot, looks like very value-heavy to me. Unlikely to be bluffing using that bet size.

Thanks, kevin2001!
I agree to both Your posts: larger 4bet and also about his river bet.

Too large 4bet... I bet around 2,4$ max here and cbet flop half pot and clear give up on turn.