It's either a check or a small bet. I think, at these stakes, I like making an exploitative half pot bet to extract value from stuff like 76,65,86 type stuff and then mostly checking back rivers. If you think that your opponents are tough or aggressive then taking this line should lead to you getting raised quite frequently here which will make checking back more appealing.

Vs the 3.5x pre, I think it's probably a slightly losing call preflop, but not a huge mistake.

As played, I think flop sizing is okay but I'd prefer either a 40% (planning to barrel 66-75%psb on favorable turns) or 75%psb to increase immediate FE, and still barrel some turns, but more selectively as their continuing range would be stronger.

On the turn, I agree with everything James said.

Call pre is definetely -ev

I would fold even vs 2BB open

Definitely would just fold pre vs an unknown..

For me personally, I will CC the SCs in CO vs UTG at some frequency (higher than 0) but it would be a low frequency CC that will depend on: 1) sizing, 2) effective stacks, 3) players behind, 4) dynamic b/w UTG player and me (did he just catch me OB bluffing river 1.3x?) etc. 5) UTG's tendencies (does he have low cbet and high x/f when missing cbet? or a ridiculously exploitable fold c-bet to raise?)

Vs. 3.5x, the effective stacks would have to be pretty deep, the players left to act would have to be pretty bad/passive to push 98cc into a CC.

Vs. a MR, I will definitely CC at a much higher frequency and the biggest thing I would personally look at is who is left to act behind, and then will mix CC'ing, 3-betting, and folding at some freq.