At the stakes I would rather just bet bigger on the flop. At low stakes just go get that value with your best hands and don't worry too much about being balanced. People will have trouble folding regardless of your sizing.

As played, definitely bet the river. There's no reason for us to believe that villain had two pair or a set heading into the river and you block missed straight draws and missed flush draws that could bluff if you check.

I agree, because it's a 3bet pot it's far less likely that you will induce bluffs from missed draws by checking. So just keep the pedal to the metal on the river. Hands like this don't grow on trees and QJ will more than likely have raised flop or turn. Opponents very likely to have a Jack for trips. Put the rest in the middle.

Agree with the above, bet much bigger on the flop and keep going with the value. You are doing much better against his calling range on the river then you are against his betting range when you check to him. So checking would only makes sense if you thought you were so obviously beaten that you would check/fold (which I would not recommend). If you would call, then its way more profitable to put the money in yourself.

I’d also bet large here on the flop for value as plenty of worst hands will call. Also bet large on the turn to set up a nice river shove.