I'll try to balance it out if it feels too grindy, it's always hard to get it right since as the developer I know all the tricks for the game. Alhough I think the parents already add 1 lust per night at 2 arousal, if you check on them in their room at night
I don't know. I frankly don't find the game that grindy at all. Maybe a bit in the beginning, but after a few weeks you have automated Essence from sexual energy at home, plus automated Essence from the Angelic Perks, plus big Essence boosts from specific events...after a while I did not even bother go hunting anymore. And aside from that, maybe it's my being an old-school gamer, but I always found that a bid of grind is good in games. It makes you feel you earned the power-ups, the new perks and the advancement in the story. Naturally, more variety* in hunting/college etc. will help in make the game feel less grindy, and you mentioned you are working on that so that's going to be ok.
*: not only in scenes, but in situations. I.e. when hunting, possibility to use Pheromones to lure prey in some hidden place rather than just overpowering them with Unnatural Strength, or something like that...I trust your inventive and fantasy in this.
P.S. yes the parents add 1 essence per night when they are at lust 2, you just have to go in their room once at night to activate it, you implemented it correctly. Additionally, when they are in that state you can easily gather another 6 essence every Saturday and Sunday evening by observing them in the living room. What I mean is that I think there are already some ways you introduced in the game to earn easy and steady Essence