I can live with 'humanist' (or 'personist', or etc), though I really was trying to aim both for 'rationalist', and to describe how Missy actually went about doing things.

As for sex - I tried to have a discreet fade-to-black for any actually adult content, while still having the protagonist in a relationship. How would you suggest, or have suggested, I manage that differently? (Or are you referring to something else?)