If you had said
Deviations from the Born rule should be derived from timelessness-cognizant game theory for multipartite systems in order to find equilibria from first principles.
that would make more sense to me, though I still don't believe that timeless equilibria have much to do with anything. The relationship between simulatee and simulator is completely asymmetric, the simulatee is at the mercy of the simulator in the Vast majority of cases.
As for the origin of the Born rule itself, I certainly don't believe it has an origin in terms of multiverse-appropriate decision theory. Quantum mechanics is incomplete, it's a type of statistical mechanics that arises from some class of more fundamental theory that we haven't yet identified, and the Born rule - that is, the feature that probabilities come from the product of a complex number with its complex conjugate - specifically results from features of that more fundamental theory; that's how I think it works.
But doesn't statistical mechanics also fall out of decision theory? Or are you saying that perspective is not a useful one in that it doesn't explain the arrow of time? (I'm really tired right now, I apologize if I'm only half-responding to the things you're actually saying.)
These are extracts from some Facebook comments I made recently. I don't think they're actually understandable as is—they're definitely not formal and there isn't an actual underlying formalism I'm referring to, just commonly held intuitions. Or at least intuitions commonly held by me. Ahem. But anyway I figure it's worth a shot.
A proposal to
rationalizederive magick and miracles from updateless-like decision theoretic assumptions:(On Google+ I list my occupation as "Theoretical Thaumaturgist". ;P )