Played this fairly passive pre but stepped on the gas post. I should probably 3b or fold here pre but I didn't think the blinds would punish my flat often enough given stats and history so I tried to get the best of both worlds as CO is raising wide here. River also seemed like a good spot for an overbet since it may look like I have a weak KdX hand that missed.

PokerStars - $1 NL (6 max) - Holdem - 5 players
Hand converted by PokerTracker 4

SB: 100.5 BB
BB: 100.56 BB - VP 53 / PR 6 / 3B 0 / AF 1 (33 Hands)
UTG: 155.04 BB
CO: 115.7 BB - VP 50 / PR 20 / 3B 6 / AF 3 (237 Hands)
Hero (BTN): 126.69 BB

SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has 9♦ T♦

fold, CO raises to 3 BB, Hero calls 3 BB, fold, BB calls 2 BB

Flop: (9.5 BB, 3 players) 4♦ 6♦ A♦
BB checks, CO checks, Hero bets 6 BB, BB calls 6 BB, fold

Turn: (21.5 BB, 2 players) K♥
BB checks, Hero bets 16 BB, BB calls 16 BB

River: (53.5 BB, 2 players) 7♥
BB checks, Hero bets 101.69 BB and is all-in, BB calls 75.56 BB and is all-in

Thoughts on all streets welcome.

I think you played it well. Dont mind the call pre flop as you are on the BTN.
I generally fast play here as well.
Looks like 2 fish are in the pot so if they catch any piece of the board they will call anyway so may as well charge them on every street!

I like your play on all streets. Occasionally you'll lose to a bigger flopped flush, but most of the time, your medium flush will be good and you'll win a stack vs flopped 2 pairs and sets (and sometimes smaller flushes).

Apparently the villain in BB tends to have a high defense frequency in the postflop. Because of this we could 3-bet preflop, because a wide range like this could call with suitable connectors smaller than ours and with a value range, from small pockets: 22-66 (with which we have a minimum advantage of 5 % on average, with respect to said value range). In addition, by 3-betting we balance our range with respect to CO, because now in a 3-way pot we are a little behind the opener of the hand.
As played the 2/3 bet on the flop is a bit big in my opinion, because we rarely have Axs here, whereas CO villain can comfortably fold with all his high aces given the texture of the board and our limp line on the preflop.
On the other hand, the BB villain will continue to call with all Axs, all sets and some flush combos (we are only beaten with mainly 3 combos: Kd-Jd; Jd-Qd; Qd-Kd). Therefore I like turn and river bet sizes. I would just try to balance more preflop and then extract some CO value on the flop with a half pot bet at most, the rest I seemed excellent overall.
Greetings.