I came across that Angeshrael piece when I happened to look him up on the PoN wiki. Awesome stuff dude! While Cure's idea of the "fire" in question being the IF has crossed my mind, I've always been more attracted to the idea that it was simply a "scrying fire", much like the one Kellhus shows to Proyas. Assuming that this story is NOT literal (and to an extent, I think most of the older tales of the Gods are indeed mostly true), then it would imply that an Inchoroi somehow posed as Husyelt (not all that unbelievable) and that the IF is something, well...mobile, for lack of a better word. An object that one can carry it around with them. For whatever reason, I do not have the impression that the IF is like that...it seems more like something that's stuck in the heart of the Ark, and thus one must travel to it. But if it is mobile, then it could have been a goad to make the Tribes of Men invade Earwa, except then we already know for a fact that they did this pretty satisfactorily with the Tusk itself.
It's an interesting question. The very early periods of Earwa are one of the most intriguing things in the series for me (mainly the origins of the Nonmen and their relation to humans, and where the Gods fit into all of this -- I don't think the Inchoroi were relevant to the origins of the peoples of Earwa). We already know the Inchoroi were tooling around and manipulating humans in Eanna, but then we also know that all these seemingly mythical stories about Gods and their abilities ended up being pretty literal. Just look at what Yatwer can do. As with many -- practically all -- mysteries in the series, it could really go at least two ways, if not more.