Preflop and flop look fine to me. Maybe you can bet the turn a bit bigger to charge him more for the flush draw. If anything the 1/2 pot bet sets up a pot sized shove should the draw miss or you improve on the river. On the turn I'm thinking he has lots of flush draws, some mid to small PPs, some Kx type hands, maybe some 8x hands. Obviously he can have some bigger hands like 88 or A4s, but those are a lot less likely and you'll usually hear from them earlier. Either with a check raise on the turn or a donk bet on the river.
When the flush comes in on the river and he checks I think I'm probably checking behind. He's pretty passive so it may just be a stubborn player that doesn't want to fold something like TT/JJ or a weaker top pair like KQ/KJ etc, but seems to me he was more likely drawing.
When he check raises the river I think he was most likely just trying to get to showdown with his mid flush and figured he might as well go all in with only 34 cents behind lol. You're probably behind, but getting almost 8 to 1 pot odds
I don't think I can fold. There are times where a fish will do this with KQ/KJ or something, or it was actually some type of weird bluff. They are known to show up with hands that make no sense
As an aside, it helps to give the sample size for the villain stats. A 28/0 over 4 hands means next to nothing, but over a larger sample it means much more. I'm sure you know this, just a friendly reminder