CO hasn't done anything out of line. A little passive, a little loose, but nothing major.

Party Poker No-Limit Hold'em, $ BB (9 handed) from (Format: Bet The Pot)

SB ($97.45)
BB ($101.10)
UTG ($103.70)
Hero ($150.70)
MP1 ($85)
MP2 ($25.10)
MP3 ($276.95)
CO ($265.05)
Button ($100)

Preflop: Hero is UTG+1 with , . SB posts a blind of $0.50.
1 fold, Hero raises to $4, 2 folds, CO calls $4, 3 folds.

Flop: ($9.50) , , (3 players)
Hero bets $6, CO calls $6.

Turn: ($21.50) (3 players)
Hero bets $10, CO raises to $30, Hero calls $20.

Standard? I imagine he would call the flop with an overpair, flush, or straight draw. Would he call with A-high thinking it's best or hope for the gutshot? If not... then what's his turn raise about?

The river was another 5 and he bet half-pot. I called down.

I think you put such a weak bet on the turn there that he felt a raise was neccesary. I think I would have bet about $15 on the turn. I think you can put him on an ace too or a 6; I am really hoping for my flush so I can push on the river. I don't know if I call a huge bet on the river here if the flush doesn't hit.

You don't raise AQs UTG+1? Is that widely agreed upon? It seems a bit too tight to be folding it, and too weak to not raise it.

I think I'm being too results-oriented with this hand, since I did end up losing. Nothing else I could have done in the hand and I don't see any clear reason to fold. The only thing I can think of... would he call a 2/3 pot bet with A-high and no flush draw? (I had AQs) He probably by default puts me on some A-high hand, so why bother with the turn-raise... unless he thinks he can get more money from me.

I hate AQ at a full table . AQ and AJ are one of my biggest leaks. If it is suited, I'll limp in from early position. If it is folded to me in the CO or on the button, then I will raise it up.

At 6 max it's a different story though

I hate the turn bet. Either fire a near pot or check. Betting 1/2 screams, "I have a draw and please take the pot from me on the river."

At 6max which is very betsy/raisey, I can raise UTG +1, BTP on the flop, and check the turn and get a free card 80% of the time. I'd check.

I bet small on the turn because there really weren't any river scare cards. I have the flush outs and I have the low-end of a straight. Maybe I made the wrong play there, but that was my thinking process anyways.