$100 PLO on stars. Temporarily 4-handed. Opponent seems solid and tricky. Opponent has more than full stack, I cover.

I get [Kh][Js][Th] on the button and open raise. BB is only caller.

Flop: [Ts][9s]. Opponent checks, I pot, opponent checkraises pot, I call.
Turn: . Opponent instantly pots, I call.
River:[Qd]. Opponent checks, I check behind.

Reasoning: most likely hand for my opponent is the straight of course, although a set is also possible. I guess that in 1/3 of the cases he is playing back at me with air. On the flop I call, since I'm currently behind against his range but have some decent draws. My hand is too good to fold there, right?
On the turn I improve but now we have a WA/WB situation, and I think that only a better hand is going to call if I raise. The speed with which he bet made me think that he decided to bet any turn. I'm less inclined to think now that he has air, since a drive-bluff on this board would be quite uncommon.
On the river there's about $60 left in his stack. Against passive straightforward opponents I might try to milk a bit more and make a value bet of $30 or so which they have to call with a straight, but this guy was capable of getting tricky on the river and checking a better boat. Also, the river card didn't exactly help me, but could have given hands like AKQT or AKQQ a better boat.

Thoughts on my play? Should I have been more aggressive?

i don't mind your flop or turn call too much. i probably raise the turn just because he could have the boat but i def see the merits of calling since unless he has the boat too or a higher boat redraw, he isn't calling with a straight. when checked to on the river, i pot. make it look like you busted a flush draw or something. no way do i see him having a higher boat here unless he's an overly tricky player. checking down loses a lot of value.