The extract you quoted raises a couple of interesting points for me, Logicus. DB and the Sith Code remind me very strongly of Nietzsche's ideas regarding herd morality and good and evil being unhelpful made-up constructs with the will to power (similar to DZ referring to the 'will' to the dark side being maximising your own power/potential?) - these two Sith lords here I think woud be eager subscribers to Nietzsche's ideas regarding morality.
But I think I've also spotted something interesting here.
DZ asserts that evil is a nonsensical concept, yet seems to exist in a universe governed by cosmic dualism - there is a light and dark side of the force which battle against each other for supremacy, and the universe is this battleground. Yet DZ seems to deny that this evil exists as the dark side as an objective force (or am I reading too much into this???)