I agree with your summary of how each life progressively becomes more extreme but I don't think moral compass or villainy comes into consideration for someone who's lived at least 600 years or 1600 if X^3 was indeed Moira's 6th life (in which she plays the game the AI's way, as speculated). Or she could be the other body in a "bath" next to Cylobel, since it appears the Librarian was talking about more than one such prisoner.
Anyway (where was I?)... right, as Totality said above, a concept like villainy looks very different depending on your time scale and what's at stake. It's the trolley problem or Ozymandias's solution. When you've lived hundreds or more than a thousand years, you're likely to see a scenario where billions can be saved if you kill or allow thousands to die. Step back far enough, you're still a hero.