Epic writing, David! Electric stuff! Absolute pleasure to read and so much to learn from!
IMO, Jonathan Haidt's excellent "The Righteous Mind" theorizes this perfectly: We are essentially intuition-driven information processors, constantly scanning the world around us, morally interpreting information and colouring narratives with our unique worldview. We readily allow intuition to lead us and then use our rationality to come up with evidence to support our beliefs. Our reasoning seeks justification, not the truth.
I'd really appreciate if you could read my article and feedback - it complements your arguments well!