I don't think we need to play this passively. Why would you give up the lead? Why not c-bet after you make TPTK?

You are giving him the opportunity to make the exact plays that he did. You showed no strength on any street, so he probably thought he could blow you off a weak king or queen. If he had a hand with any weak showdown value, he would most likely be checking.

Villains bet sizing is setting up a perfect river shove. People don't always bet less when they have good hands. In fact, when blinds are 20-35 BBs deep this sizing pattern is common to be setting up river shoves. Good players will be doing this with all nut type hands, busted draws, and occasionally air. So when you estimated villains sizing if he/she had AK (which is hard because we have two blockers and the board has one), it doesn't necessarily have to be like that.

I think villain plays his nut flush draws like this, its totally conceivable that villain flatted AJdd or A10dd here (because the K and Q of diamonds are accounted for. That does make it harder for him to have some busted draw hands like this) I think AJs makes a lot of sense, nut flush and a gutshot. KQ is also likely. But by giving up the lead and just calling its really hard to know where you stand. If you really want to check, why not go for a check raise? Most likely for value, and if you get shoved on you can reevaluate.

Why fold river? The 5h changes absolutely nothing. If you thought you were ahead on flop and turn, you are most certainly still ahead now. Its just hard to imagine we don't have the best hand.

Also, you say he's trying to trap with premium pairs? Like what pairs did you have in mind? Since you opened in early position, villain is more likely to 3bet with value hands because you are likely to have a strong enough holding to call. There is one A, two K, and one Q spoken for making it harder for villain to have these holdings, but I think AA and QQ are just usually a 3bet in tournys like this if villain had them.

I think its a call personally, but I don't think you should be giving up the lead here. I would only give up my betting lead if I smashed the board and my opponent was super aggressive. Giving up the lead is what put you in this situation.

As played I never fold this, buuuuuuuuut i never plays like this. I think cbet is always better option here, but, lets think the way u play:

What is your range in this spot c/c? JJ, TT, 99, 88, AQ, QJ, QT and sometimes K9s KT KJ.
If villain think the game, he always barrel this spot, cause your range is weak and fold a lot in river.

Other thing is that we need to think is, based on your weak range, villain with value always bet small in river if he thinks in ranges, trying a value bet. He is so polarized river...

(sorry bad english)