Very good point you make at the botton of your post. Something people should always keep in mind.
To me--and I'm sure others feel differently--there's a huge disconnect in what you outlined. I'll try to explain as best I can.
Meteion is the threat to Etheirys and the Final Days is what she's going to bring to Etheirys. You would think, then, that the thing that should be on the forefront of Venat's mind, what she is working towards, is stopping Meteion before the Final Days occurs. If the Final Days doesn't happen, then Zodiark doesn't exist.
Now, it's possible that she attempted to do this by herself, failed, and had to allow Zodiark as plan B--but there's no evidence of that in the game. What appears to happen is Venat told no one, gathered followers to oppose Zodiark (not Meteion), allowed him to be built with the lives of the people around her, and then (fundamentally) stole him for her own purposes.
Then in the 12,000 years that followed, she fanned the flames of discord between her blessed and the Ancient survivors. Surely, by the time the world was Sundered, at the beginning she could have told Emet-Selch, or Elidibus, or heck, depending on what he was like before he went nuts, Lahabrea what her plans were. Hermes was no longer there as a threat, having fulfilled his purpose to assist with the building of Zodiark as a dynamis shield. If they were still too infuriated by what they saw as betrayal to ever work with her, at least they would have made that decision while knowing there was a larger threat growing stronger and stronger as the centuries passed.
I've no doubt people disagree about what's subjective. The past two years have taught me that individuals have fundamentally different beliefs on what is right with some feeling fully justified in forcing others to adhere to their version of it. It doesn't, however, give them an excuse to act against others. Near as I can tell, the Amaurotines had a democracy that was overthrown by Venat.
Considering the writing of the expac, I'm sure they would have been all fine with this and would have lined up to kneel and kiss her foot and praise her for teaching them, the dumb nostalgic old grumps, all about hope (tm), love, life, and laughter. And, of course, to Move Foward, Move On, Forge Ahead (tm) together to the Better Brighter Future (tm) while saluting the flag of the United States of Alphinaud.
Thanks for your view and opinion on the matter. As for me I am indifferent I have seen plenty of heroes do villianous acts and villians do heroic acts. So it no longer holds shock value for me. I have witness good guys sit bye and let good people walk unknowlingly towards death or with hold dire information.
No character should so morally correct and infoulable that they wont make or take actions that go against whats expected of them. But this is my view and opinion though.
I agree that sometimes good characters do bad things, but I don't think I've seen a good character as untrusting as Venat is.
I'll use an example from Endwalker. Imagine if, after we killed Zodiark, we told absolutely no one that the Final Days would restart due to him no longer shielding the planet. In fact, we don't tell anyone he's dead. Even further, if we, in fact, swore the Watcher to secrecy about this, because we were "afraid the citystates would panic" or "Urianger isn't as trustworthy as I'd like, so it's better to keep him in the dark."
Then we watch, silently, as the Final Days begin again. We watch as people die, forever parted from the aetherial sea and the cycle of rebirth. We watch as the Scions desperately try to figure out what could have possibly started the Final Days up again, wasting time and covering ground we already have intimate knowledge of.
But, since we're not Venat, we did what we did instead.
That brings up a point I'm curious about: Meteion mentions that she has an egg that she's storing souls in so they won't be reborn. Does getting rid of the Endsinger allow the Blasphemies to actually go to the afterlife? The egg thing did crack before the final dungeon.