Feeling a little weak with TPTK

Both villains are about 35/7. Semi-Loose passive mini-fish.
Is this line too weak with 2 callers? I figure KJ or T9 or any J is likely here. If I am raised on the turn I have to drop the hand, so I just check/called. Too weak? Should I be betting/raising to protect against any , K, or 8? Please leave me some detailed feedback on how you play the hand and why?

Hold'em NL ($0.25/$0.50)
Seat 2 is the button.
Seat 1: FoldIt ($18.60 in chips)
Seat 2: discob ($51.80 in chips)
Seat 3: kroko17 ($66.67 in chips)
Seat 4: nesla ($50.80 in chips)
Seat 5: HERO ($42.75 in chips)
Seat 6: pdizzy sits out
kroko17: posts small blind $0.25
nesla: posts big blind $0.50
----- HOLE CARDS -----
dealt to HERO Q A
HERO: raises to $2
FoldIt: folds
discob: calls $2
kroko17: calls $1.75
nesla: folds
($6.50)----- FLOP ----- T 9 Q
kroko17: checks
HERO: bets $5
discob: calls $5
kroko17: calls $5
($21.50)----- TURN ----- 6
kroko17: checks
HERO: checks
discob: bets $5
kroko17: calls $5
passdsuga: calls $5
($36.50)----- RIVER ----- 4
kroko17: checks
HERO: checks
discob: bets $10
kroko17: folds
HERO: calls $10

I even thought about folding the river to a big bet, but getting 4:1 on my money I felt compelled to call? What if he bets $20? Up to how much can I call here?

I actually think you played this OK. The only thing I don't like is giving odds to draw on the turn ... but discob is not playing this like a draw. If he wanted to draw cheap, he'd check behind the turn, if he wanted to semi-bluff he'd have made a man sized bet.

Since you are PFR, you can hardly rep 89 (KJ?) well enough to blow someone off their tp/set. I think disco's probe on the turn indicates mid-pair good kicker or q-mid kicker. kroko is probably on a draw (obvious when he folds blank river).

Nothing about this hands screams out that you should raise turn or river, and I wouldn't fold for so little. If he bets 20 on the river, I think you can still call, but cry more often. Pot sized bet is very close to a push for villian, that is approaching the lay down zone with TPTK here.

nh. letting them draw free/cheap is bad, but keeping pot small is good. He can easily value bet KQ on river, maybe even KT.