forgot to tell we are in the money but far from the FT bubble.

Obviously I'm not a pro - but i used to be SNE on Stars playing MSS - fold preflop/ if you are postflop check back turn, call river

In late stage against that 3bet and 3bet resteal, I think there is no need to turn your hand in to a bluff with a 4bet-fold. I think your hand easily dominates his 3bet range, so I would just call, even if his 3bet is almost 3x ( you are both deep and I expect al of his 3bet range OOP to be 3x at those stacks). Post flop play : I would have called the flop. After that I would have checked back the turn because at that point : 1) he has has a hand that beats you like A9, 99, AJ, AQ,AK; 2) he has a pair like 88 to KK and against a decent reg you will only get only 1 street of value anyways, so it's best to get it on the river; 3) he has air, which will make it possible for him to bluff the river if you check the turn, naturally I will just call if he does so. ; 4) this a rare situation and for this I have a question also : What would you do if he check-raises all inn the river and you have to put like 150-250k in 600k ?, I know that he rarely has a bluff here, but I am always stressed by this kind of situation because the correct mathematical call, which I don't think that counts to much in this kind of spots. So an answer from a very experienced player will help me get over this :)