7 handed 50/100 PLO

UTG+1 (xx)
UTG (xx)
MP ( 15k ) 150bb
CO ( 28k ) 280bb
BTN hero ( 100k ) 1000bb
SB ( 10k ) 100bb
BB ( 30k ) 300bb

All players are sooooo loose and passive except player on the MP who can be sometimes aggresive.

hero has AsJsJc3c

preflop:
UTG+1 folds, UTG folds, MP openraise pot to 400, CO reraises to 1200, BTN hero repots to 4200, SB folds, BB folds, MP folds, CO tanks for like 2 minutes and calls

flop 2 players
pot: 9000
Qs5c9d
CO checks, BTN hero bets 7000, CO calls

turn 2 players
pot: 23000
Qs5c9d 2c
CO checks, BTN hero checks

river 2 players
pot: 23000
Qs5c9d 2c Ks
UTG shoves his last 16800, hero obv folds

he shows me KQ and told me, that he was value betting against aces.

I think that preflop is interesting, since CO is somewhat competent - he can make plays ( bluffs ) or somewhat reasonable valuebets and he can raise his hands preflop. I was 4betting to isolate my decent hand HU since I am blocking one A so it reduces probability of them having aces preflop.

On the flop I have 2 backdoor flashdraws and blockers to the straight, so I decided to bet and if straight comes I was ready to snap pot it.

Turn gives me weakish flashdraw and a gutshot, so I dont wanna get check Jammed or I dont wanna get it in bad, so I just check and decide on the river - again my plan is to jam on straight completing river cards.

River is easy fold since he shoves, but if he was about to check I would have just shove myself.