It's curious thinking about dualism and nondualism. You make a stirring case for nondualism as a virtue and as a perspective on life and the world. I've long thought of it that way, though for years unfamiliar with the term. (In my 20s I was fascinated by Carlos Castenda (Don Juan) and also Existentialism.)

That said, it's always struck me that dualism is the Natural Attitude (Husserl's term). Nondualism as a perspective seems like something one has to become enlightened and/or practice to attain and maintain.

Do you see any connection between nondualism and Heidegger's concept of Being? At least in his later years he wrote approvingly of Parmenides' concept of all being One.