Prophets and/or Shaman must have the ability to create.

Absolutely. I'd love if Achamian just dragged Mimara to the armies of the Great Ordeal and demanded that she declare Kellhus false... and then Mimara can lie and declare him true . Imagination's running wild.

Mark is proportionate to skill, friend. Kellhus in TTT still needed Achamian to protect him. Twenty years later. Kellhus either looks Quya, Titirga, or something different... certainly not a normal human sorcerer.

Welcome to the Second Apocalypse, Camel.

Mimara may or may not see the 'objective morality' that Bakker is referring to.

We don't know that Kellhus is a False Prophet; I think we impose that upon the narrative because Kellhus doesn't seem to exhibit what are, ultimately, probably culturally projected (possibly global-culture) "prophet-like qualities" (though I am inclined to believe Mimara's has access to a (possibly) most omniscient perspective of the narrative world, so far, but we just don't know, again, the validity of her perspective). We also haven't seen Kellhus through the eyes of the Few in TAE series yet... perhaps, Kellhus has a mark like the Cishaurim or Titirga, whom may or may not be Damned as other sorcerers seem to be (Titirga from The False Sun short story on Bakker blog - apparently, major spoilers for The Unholy Consult because it offers a pre-apocalypse Consult perspective, which is also probably imminent in TUC).

Bakker has said that innocence is key to redemption in Earwa (suffering has also been mentioned, I think).