This is a hand on UniBet, Effective stacks are 100BB

UTG is a fish and opens 2x, the button calls and I call 1bb with Kh2h
This is a loose call but i'm getting 5.5/1 and UTGis a fish. Would it be best to just fold this and move on?

Flop
pot ($0.65)
Js4h6h

Hero: checks
UTG: checks
Button: bets $0.32
hero and UTG call

I pick up a flush draw and an over, I decide to call but I feel a x/r might have been best here, to build the pot and to make a bluff more believable on later streets if I miss

Turn
pot ($1.61)
7h

Hero: checks
UTG: checks
Button: bets $0.80
Hero: calls
UTG: folds

*I make the second nuts but decide to play it passively because I felt villain had a jack and would fold to aggression, also ace high flushes are part of his range. Would a raise and GII be best here? *

River
pot ($3.21)
Jc

Hero: bet $2

I decide to go for a bet/fold line to try get value from a worse flush or a jack. Would a x/c be better here?or a check/raise/fold, depending on his sizing

Any feedback appreciated. A fold pre would probably be the best option giving I have no info on the button.