I only have 31 hands on the villain, but he is running at 45.16/0/1.25. Not a huge sample, but from his play thus far, he seems pretty fishy.

Full Tilt Poker $0.25/$0.50 No Limit Hold'em - 8 players
The Official 2+2 Hand Converter Powered By DeucesCracked.com

UTG+1: $76.65
MP1: $49.25
MP2: $50.00
Hero (CO): $51.35
BTN: $59.00
SB: $100.25
BB: $100.00
UTG: $51.05

Pre Flop: ($0.75) Hero is CO with K Q
UTG calls $0.50, 3 folds, Hero raises to $2.50, 3 folds, UTG calls $2

Flop: ($5.75) 2 3 Q (2 players)
UTG checks, Hero bets $4, UTG calls $4

Turn: ($13.75) A (2 players)
UTG checks, Hero requests TIME, Hero bets $8, UTG calls $8

River: ($29.75) 8 (2 players)
UTG bets $23.50, Hero requests TIME

Preflop and flop are pretty standard I think. Isolate/cbet with top pair. Turn is meh, I still wanted to get value from a flush draw since there are two possible draws, so I bet. Feel free to criticize.
River seems odd. Obviously once he calls the turn, I think there might be a few aces in his range, but I don't think he ever leads with them on the river. He just seems like the type of player to c/c with an ace here. Both flush draws missed, so can I call here to catch a bluff?

Passive players don't become aggressive without a hand. The best broken FD hand you beat is KJ of hearts. I think this is an easy fold.

Flopbet is fine obv and I really like the turnbet: too many people check behind here, missing out on value against a lot of draws, weaker Q's and some other trash he's calling with (underpairs mainly).

River looks tricky and in the heat of the game I usually tank and dive into the previous HH's from this table to see if I can find anything that might show he's an spewy aggrotard. However: most of the times, it's gonna be a fold.

If he made it 31,5 on the turn (23,5+8), we would instsamuck, he's now doing basicly the same, only he allows another cheap card before he puts the extra 23,5 in and committing himself.

Imo, folding should be standard unless you have a good read he's spewing chips.

I don't think fishy players turn into aggrodonks on the river without the a hand that beats top pair.

Maybe he has a pair of 8's he can't let go of? When a fish shoves, its usually safe to assume they can beat top pair. If he keeps doing this, make a not that he turns into aggrozilla on the river.

A probable station is betting when we have a weak hand that may even be behind his bluff range (Axhh for example)

Easy fold.

I would generally advocate a DB here [pretty much any non heart, and even a heart as a b/f], but that funky ace hits most of his drawing range, so it is very tough to actually get vale with it. Tbh, it even hits some of his funky gutter drawing rng that a 45vpip can have here.

But yes I think its a river fold, i dont rly think he has that many bluffs in his rng, and while it might be a bit polarized, i think it is super heavily weighted towards hands that own us.

timing is pretty key here, like if he called fast on the flop and tanked on the turn then somethings up. if you didnt notice/dont remember timing then SNAP call this, you'll see a FD soo often. if he called fast on the flop and tanked on the turn i'd be a little concerned about 45 though.

I would fold river.
a check call check call bet line is often a strong hand.

even on this drawy a board? Shouldn't villain CRAI on turn to protect his hand? Or because he's a fish, we are assuming he doesn't know he needs to protect his hand?

you played if fine on flop and turn.i fold on the river,and it shouldnt be close,there shouldnt be too many missed flushes in his range but i see him playing A2 Q8 45 etc like this

Pre, flop and turn were played fine. The river, tricky spot, but I favour a call. Fish often lead the river on a missed draw recognizing that they can't win at showdown, but not realizing they can't rep very much. I'm not sure what two pair or better hands would take this flop/turn/river line other than Q8. With A2 A3 I would expect a check raise on the turn. On a marginal decision, I favour a call to gain information.

Given that the villain never raises pre, there is a ton of aces in his range. All sorts of random 2 pairs and staff are also possible. I guess on turn, you want to get value but also pot control given your weak hand. I go for pot control on turn and call a small bet on river/fold to a big bet

I actually like calling here.

Would be kind of lengthy to explain why, it's a combination of villain repping a super narrow range, weird players often doing incredibly weird things on the river (esp when they miss their draws) and bet sizing...