QQ - Bad river card

I don't like checking because we can't really call a big bet. I would bet very small, like 5BB, and fold to a raise. It's probably not a thing a theory but should be fine in practice as I don't expect them to raise as a bluff.

I was gonna say check fold but boulgakovs line sounds good

I would go larger on the turn - A lot of pair+draw that will call and some 8x will have called the flop. Some rivers will suck, but for this SPR you can shove the safe ones vs the half stack.

The ace hits a lot of flop/turn calls - All the pairs with an ace kicker/A5/A2/A7/diamond draws. I would imagine most of the 1 pair Ace hands will check back the river with pot being quite large and the board connected. Also plenty of the flop draws also have a pair on a board like this and are likely to check back.

Bluffs would come from the diamond broadway part of their range - It is useful to know if the villain is say 40vpip/20pfr vs 40vpip/0pf, the former should have less missed flush draws due to raising broadways.

As played as above said, block works well, especially if villain is passive. If I check I will fold to any decent sized bet.