I'm typically a fan of protag-centric games, as in MC is the only male that is ever involved with girls. Haven't played since the last update, but I remember the (skippable) scene with Ethan and his mom being pretty inoffensive. IIRC it was made pretty clear that Ethan's mom is not a LI, probably never will be, and the scene's main purpose was to help break down MC's hangups about incest, queueing things up for MC later on.
Dev has shown he has no problem killing off female characters, so I feel like *if* Ethan ends up dead in the future, his mom will likely meet the same fate. However, considering Ethan is a doctor, and highly resourceful, odds are he'll be around for the long haul. Maybe dev meant to reassure us that Ethan isn't a threat to MC, since he's clearly happy with his sex life.
I didn't care for the option to wingman for another guy to get with one of MC's LIs, but IIRC there was a single choice, and choosing to shut it down almost entirely eradicated the other guy from the game. Thus, that whole situation didn't end up bothering me much.
Now I'm off to try the new update, but I'm gonna go ahead and restart, since it seems dev changed a lot of stuff from earlier versions(roughly 3000 lines of dialogue based on my progress tracker).
Edit: After replaying the game from the start, it seems that all the new lewd scenes for the 0.40 update take place *before* the end of 0.30, so if you load a save from the end of 0.30 you *will* miss all the new lewds. The "go home" route leads to Alice solo path or Alice/Nina path, but may allow for more LIs to join in future updates.. The "go to school" route seems to be the way to go for the early harem. Gives the option for any combination of Alice, Amber, Green, and Nina. Those 4 appear to be the only actual LIs in the game thus far, and the only 4 with a "love" variable.