If your table is tight enough to make opening QJo from EP profitable, then why do you need to open to 3.5x?
Either bet the flop or check-fold. That you had been cbetting a lot only matters if you believe (a) he has noticed this and (b) he'll play differently as a result.
Calling in the hope of bluffing
spades on the turn seems at least somewhat inconsistent, If you've been cbetting a lot, there's a decent chance you've been cbetting your draws. So why expect him to think you check-called with one this time?
Granted the opponent may not think at this level, why is it important to try to outplay him on this hand anyway? KISS
Your stated assumptions on the turn don't seem fully consistent either. He's playing tight but he calls 3.5x with T9, then bets the flop with only a gutshot? It's possible, but how likely? It also seems reasonably likely a tight player would fold QJ pre-.
So was he tight or not? you can change your assumptions during a hand, but I'm not seeing nearly enough reasons to do so here.