Thanks for including reasons for skepticism. I find them quite likely - there is no actual argument that the MMEU rule gives better outcomes than classical EV maximization in these thought experiements, just that many humans seem to prefer them in the real world. And in the real world, where this kind of perfect knowledge of uncertainty and idealized payoffs are not possible, all of those biases are pretty reasonable, so it's easy to understand why they're baked in for most of us.

The lack of rationality is most clear in your first example. If you reject bet 1 or bet 2 in the case where you can't take both, you lose utility. This seems pretty clear. That's not "alternate rationality", it's just an error.

Some of the other cases, where there's no average utility reason to prefer one choice over the other, I have less-strong objections. I don't think it adds any rationality to have those preferences, but it doesn't cost anything.