I am finding this a difficult hand.
Btn is unlikely to be betting just because 3 people checked. We have 2nd nut flush draw, middle pair, we block ourselves with the 88, and a Q turn doesnt really help us as KQxx AQJx QJ9x type hands also improve.

I can see myself checking hoping it checks through and I can stab at some turns, but I think in this spot I would take a stab at the flop and be happy to take it down. If we are raised off the hand it is unlikely we are conceding significant equity by folding. If called once we can pressure some turns, and if called in more than one spot we likely need be done with the hand for the most part.

Tough one. I would prefer to bet the turn as a blocker rather than the river, but if I am betting the river I wouldn't go for full pot, it's a strange line and just costs us less if we're raised or called.