Ethan is blackmailing her with a sextape and is forcing her to do that escort work (or however u wanna call it) cause he wanna fuck her, there's also the memories from MC's past...i don't know how he could anything else than the bad guy with what he does. No theoretical sob story of his parents being mean to him would justify what he does, neither if he ust works for someone else.
So far there isn't even a hint that there is some other bad guy, or some other conspiracy going on. Out of all LI's it's only Erynn which has this kind of dark drama going on, all others are rather easy going in the drama aspect.
As u said the said, the virgin is really jealous of the MC, first Layla, than he doesn't believe for a second the thing with Elena and lastly Valerie likes the MC and not him...well and Ethan is manipulating him, which seems rather easy, as Zack is a brain dead idiot. But yes harmless.
What support ? I think there is one ending where the viking dad of MC's ex helps him, or Valerie kicks Ethan in the nuts, at best Ethan knows that MC has a friend.
Not sure what u mean with removing Erynn from the story, but Ethan hates the MC for many years that won't vanish just cause Erynn is out of the picture.