$100 NL on UB, Full ring, I have $110, villain covers.

Reads: I've played a lot of PLO with villain, who plays that game very aggressively and who is also quite tricky. I don't think he's a huge winner though.

I call villains UTG raise to $4 with 99. SB and BB also call.

Flop: [Jh][Qs]. Checked to me, I bet $15. Only villain calls.
Turn: . Villain leads for $15, I call??
River: . Villain checks. Can I bet for value here?

I'd definitely call the turn like you did - you don't want to commit yourself with a raise if he did make his straight or flush, and by calling him it looks like you aren't afraid of the straight or flush.

I'd just check behind on the river though - what can he call you with here for any value bet? Maybe K-Q or A-Q, or J-Q, but even then he might let them go. I doubt any aggro player likes to check call on the river - he's either check-folding or check-raising, so you might as well just check behind too.