Can we raise OTR?

Just call and make a note.

Passive player takes aggressive line. I suggest a fold in this spot. Your J high flush doesnt beat that much. You are often facing a higher flush. Could be that he is value raising with worse. Like trips overplaying and there fore this spot is close and could call or fold, it doesnt matter that much. But this is nowhere a value raise it doesnt beat a lot of his big range.

If we are to fold, then we should xc river.

Passive players like to call more than to raise or bet, and therefore a bet is more than ok to not too lose value. But when passive opponents makes raises we have to be aware of his tendency and fold more than calling or raising depending on our holding.

AF 5,5 is not a passive guy...

61/8 is quite passive, at least preflop and they are more often then not also postflop. AF 5.5 isnt saying that much.

Passive preflop does not mean passive postflop. He has shown action postflop. We cannot treat him as passive.

But look to the board, what do you beat here besides total random spew?

A2 ...

He had 4♣:3♣:

Weak flushes.

Yep, call. Folding is out of the question. He has mostly flushes, trips and random bluffs. A set is never checking back turn, so you are right to think about 3betting the river but its extremely exploitative and you should have some info of how he plays his flushes.

I would never 3bet flush on paired board, but also would never fold in this spot.

35c to win 87c
imo good odds to call
edit: interesting bluff on F, i would give him more A2 than flushes too

I would cbet this OTF and with this runout I would bet bet bet.

Would you fold vs the river raise?

Yea. We don't have nut flush and board is paired. I don't expect villain to raise as a bluff there often.
Maybe we could just x/c OTR too or something. But the main point was that I would cbet flop and when we hit FD+gutshot I would often just fire again.

I think that if we will fire river and then fold, then it is better to xc.

I think that if we are going to x/c flop, that we should instead bet out since we have to the betting lead and a gutshot. When we pick up the FD on the turn we can bet again and we can also bet the river for value.

In this exact spot I think that we can call the raise on the river. Your hand is extremely under represented. So I don't think you can fold to the raise.