Cadfan, nice analysis. That's interesting, if not intuitive. Accuracy I freely admitted was better, but I did not think damage would be. Huh. Well, I stand corrected.
I still maintain, however, that
Flurry of Talons is the better tactical option. If you consider a 1d8 weapon, all else being equal, you have a higher accuracy and untyped damage for
FoT versus
Shadow Fire. However, I am drink at the moment, so you can hold that against me.

However, factoring in the differences in average defenses amongst monsters as calculated earlier by... er, I forget who. Anyway, factoring those in, and also the probability of a monster with fire resistance, I think
FoT wins out. That may change with weapons with a higher damage type though, and I'm not about to do that math right now. Verifying yours tired me out.