Is this river call a punt?

Pre flop : I think is standard. The sizing villain uses for 3b is massive - almost leaned toward jamming as we started hand w 102bb's effective. Thoughts on flatting here vs jamming? I actually think either is fine. In general, 3b out of the BB tend to be weighted more towards value hands from my experience. Anyway, we decide to flat vs jamming.

Flop : Villain bets 50% pot. I think flatting here is the only option we have after flatting villain's 3b pre flop. I lean towards flatting as villain will have range advantage (he can have AA,KK & we cant). Additionally, if villain have hands like TT,JJ, AK we want to allow him to continue betting later streets. I am okay w flatting flop.

Turn : Villain checks after the flush comes in. I decided to check behind. If villain has a hand like AA,KK (especially w a diamond) then we are drawing near dead. Also, we do not contain a diamond in our hand so in theory, it makes it more likely that villain will have flushes as we unblock AKdd, AQdd, AJdd, ATdd. If villain has TT,JJ w a diamond it will suck on river diamonds as he will get there vs our hand. However, I think I am okay the turn going x/x. Any thoughts/ insight on this turn check? If betting is more optimal, what sizing would you guys be using?

River : Villain bets about 80% pot. I think our call on the river is a punt. The only hands we are ahead of, as played, are TT-JJ w a diamond which idk if most .10nl players are turning those hands into bluffs vs trying to get to showdown, or AK w a diamond which I think would barrel turn instead of x'ing. That leaves Axdd hands as well as AA,KK which we lose to both. I think we should be folding the river when villain bets this size. Bad call on my end - I have been making a lot of those lately, unfortunately. Again, any thoughts/ insights to the river I would be happy to hear. Thanks in advance.