Some people advocate to squeeze here. But I think flatting has to be ok too. I'm not aware of squeezing ranges, so if you have a source for any, let me know. Ayways, the SB is a loose passive with pfr/vpip 70/24 so I guess in this particular situation we want to flat. Co is quite loose as well.

SB donking makes me think he might have a draw or he hit his 3 because he's just way too loose passive. CO calling I think his range is either trapping with 2pair+, or has some draw. I think I'm getting value here if I raise so I do. Is sizing alright?

SB is draing at best, but possibly holds something trashy. CO either drawing, either trapping with 2pair+ or has a low A.
I didnt bet at the time because I was afraid of sets. Looking back I'm pretty sure we should bet here to get value from draws and worse aces.
If that's correct what should the bet size be here?

I'm not happy to call, the hand I'm most afraid of is AT but he could also bluf with mssed draws, right? especially since I checked turn,
I'm not afraid of SB because most probably has something really trashy. What do you think CO's range is here?