... and my mother, who was an evangelical Christian.

Bullseye.  I knew only a Protestant could have come up with something as Bibliolatrous as the Tusk.

My pet theory is that they are fleeing from someone else (another species of a non-depraved faction of their own race) who were trying to exterminate them. Their motives don't parse otherwise, since they are biologically immortal and had interstellar levels of tech, so they had no real reason to fear damnation unless someone was actively trying to end their lives. This will probably not pan out, but my crackpot is dear to my heart.

Other pet theory - they are full of shit about Earwa being the promised planet of "salvation", there is nothing that can shield them from Judgement because the force they are trying to fight against is the cause of the cosmological structures they are attempting to wield as weapons.  You can't seal the World from the Outside when there is Someone in the Outside Who causes the World to exist in the first place, all He has to do is unmake your defensive measures and there you are.  I look forward to seeing the Inchies rage out like mad when they realize this.

No one wants damnation, but what the Inverse Fire shows, perhaps, is so factual, so seemingly determined, that it grants you escapism through the most extreme nihilism.  Damnation is insurmountable, salvation seemingly unobtainable, so hence why the Consult takes the alternative route of disabling damnation, not seeking salvation.

This has always been the oddest part of Bakkerverse's theologies to me.  There is literally no discussion of atonement and salvation on the part of anyone, even in regards to Inri Sejenus, which is a weird and glaring omission given that Sejenus is Not!Jesus.  The closest thing you get is the mention that some of the Hundred will save you to their particular, presumably customized and this distorted, paradise if you are a good customer of theirs. It's curiously lopsided.

The end result of mass automation will be the return of the sort of social structure you see in Downton Abbey: a relatively small class of very rich aristos and a larger class of people who sell their labor as domestic servants.  This will occur because there is one thing a servant can give an employer that no machine ever will: the prestige of being able to command another human being.  People crave status, rank, distinction, and power, and being able to issue orders to people who are recognizably your inferiors generates social status like little else in the world.  Once it becomes clear that employment has undergone a permanent structural shift, this will become acceptable within a generation. 

Speulation, the alleged deleted scene is kellhus eating the heart after he brandishes it

I wish Kellhus could learn by eating brains. 

I bet he does too.

new end to TUC: Kellhus wipes out the Consult heirarchy, seizes control of the Derived via the Mog Apparatus and boards the Ark with the Derived, the Great Ordeal, and the Dunyain.  the Ark is repaired and launches towards the Nail of Heaven which is revealed as the Inchoroi homeworld.  Kellhus pulls an Ender Wiggin move: permanently eliminate the threat at it's source

while i'm thinking about it--Inchoroi motivation still baffles me.  i can't understand why they would incur unnecessary risks while their stated goal is to avoid damnation (like antagonizing nonmen).

That's always been my take as well, their rational course of action is to just stay near Golgotterath behind half a continent of sranc Bashrags and Wracu and amuse themselves with what they have there.  They are immortal except when killed by violence and everyone else except the Mandate thought they were dead.  No need to rock that boat.

so Aurang and Aurax anticipating reinforcements?

My pet theory has always been that they were running from others of their own kind, or maybe a second alien species, who are uncorrupted - the xenos equivalents of Proyas, in other words.  Probably can't work, but it still sounds fun.

Better point - since the Inchoroi are damned because of their "lifestyle choices", so to speak, and those seem linked to their mastery of the Tekne and subsequent embrace of hedonism - that would imply that prior generations of their species are not damned out of hand since those conditions came into being at a certain point in their racial history and would not condition the salvation of earlier members of the species.  Could Kellhus have talked to redeemed Inchoroi from ~ 100 years or so before their total collapse into perversion while he was jaunting about the Outside? Seems like a smart move to attempt at least.

If that should prove to be true then I would stand refuted, but I can only think that the Tusk is basically accurate in light of the fact that at least one of it's deities (Yatwer) has apparently manifested herself to her worshipers.  It is worth noting that Kellhus does not seem to question the reality of the Outside or it's agencies despite having more or less every incentive to do so.