I think you should be betting far smaller on the flop here. Solvers tell us that we should be sizing right down on monotone boards, and I think that'd be amplified in multiway pots. It also allows you to go wider for value

I think river is a fold, although there are many exploitative considerations, some of which could make it a call. In general I don't see players run this bluff often enough. However with more reads you can make more nuanced decisions. If villain uses AQ, AJ, KJ with a heart to bluff, the I prefer calling with sets over QJ as QJ blocks bluffs, whereas sets don't (this assumes he doesn't value bet worse than flushes). If he uses hands like AhTx, Ah9x etc. then I prefer calling with QJ over sets. I don't think many people do this though and most people don't have those hands pre.

I think it's a fold both in theory and exploitativaly, unless you had some other type of read

I think players underbluff in these spots, they tend to choose a more passive lines with their draws. I think it's fold on river, he should have ton of flushes, and shouldnt be jamming his sets on a river

I would fold OTR, a passive player, in general, wouldn't take a line like raising flop, barreling turn and bluffing river with AhX, I think they would just call flop and hope to hit their flush OTT, his line seems very value heavy as QJ or flush, I don't even know if they are taking this line with 99/88, so folding kinda sucks but seems a correct adaptation to a passive player.

3bet pre
size down with most parts of range on flop
rest seems reasonable if we have enough quity and implied to call, i'm not a math guy and im too lazy to work it out but whatever, probably reasonable line, exploitably this sizing vs weaker opposition is fine