It's possible, though it somewhat depends on your definition of "no sex".Im pretty sure that you can run a no sex route and still get the Slut Ending.
Sadism level has an effect on which ending you're getting, so if you get very high sadism, you don't need all that high of a slut level to get Good End.
Masochism has an effect too, but Masochism levels are pretty heavily tied to losses and sex acts.