I think you're correct in raising the general issue of what hypothetical problems it makes sense to consider, but your application to Newcomb's does not go very far.
Personally, I can think of LOTS of reasons to doubt that Newcomb's problem is even theoretically possible to set.
You didn't give any, though, and Newcomb's problem does not require an infallible Omega, only a fairly reliable one. The empirical barrier to believing in Omega is assumed away by another hypothesis: that you are sure that Omega is honest and reliable.
Personally, I think I can reliably predict that Eliezer would one-box against Omega, based on his public writings. I'm not sure if that implies that he would one-box against me, even if he agrees that he would one-box against Omega and that my prediction is based on good evidence that he would.
Personally, I think I can reliably predict that Eliezer would one-box against Omega, based on his public writings. I'm not sure if that implies that he would one-box against me,
And since any FAI Eliezer codes is (nearly) infinitely more likely to be presented Newcomb's boxes by one such as you, or Penn and Teller, or Madoff than by Omega or his ilk, this would seem to be a more important question than the Newcomb's problem with Omega.
Really the main point of my post is "Omega is (nearly) impossible therefore problems presuming Omega are (nearly)...
EDIT: I see by the karma bombing we can't even ask. Why even call this part of the site "discussion?"
Some of the classic questions about an omnipotent god include