After a good night's sleep, here are some more thoughts:

the idea is that you pay up because you feel obligated to your counterfactual self.

To feel obligated to my counterfactual self, which exists only in the "mind" of Omega, and not feel obligated to Omega doesn't make any sense to me.

Your additional assumptions about Omega destroy the utility that the $100 had - in the original version, $100 is $100 to both me and Omega, but in your version it is nothing to Omega. Your amended version of the problem amounts to "would I throw $100 into an incinerator on the basis of some thought experiment", and that is clearly not even a zero-sum game if you consider the whole system - the original problem is zero-sum, and that gives me more freedom of choice.

I don't see how your points apply: I would have paid had I lost. Except if my hypothetical self is so much in debt that it can't reasonably spend $100 on an investment such as this - in which case Omega would have known in advance, and understands my nonpayment.

I do not consider the future existence of Omega as a factor at all, so it doesn't matter whether it self-destructs or not. And it is also a given that Omega is absolutely trustworthy (more than I could say for myself).

My view is that this may well be one of the undecidable theorems that Goedel has shown must exist in any reasonably complex formal system. The only way to make it decidable is to think out of the box, and in this case it means that I consider that someone else is somehow still "me" (at least under ethical aspects) - there are other threads on here that involve splitting myself and still remaining the same person somehow, so it's not intrinsically irrational or anything. My reference to Buddhism was merely meant to show that the concept is mainstream enough to be part of a major world religion, though most other religions and the UN charta of human rights have it as well, though not as pronounced, as "brotherhood" - not a factual, but an ethical identity.