I think the Path Tracker really needs to be upgraded. There's no shame having it be more like Once In A Lifetime, or more other games with a similar harem tracker. I just feel this one is too empty. Effectively all it shows is their face and name. I'm assume, like OIAL, if you fuck up the girls will get greyed out or removed, but I wish there was more information there.
Given how you openly admit heavy influence from OIAL, that implies certain aspects are going to be present. Obviously incest is there, but what about pregnancy etc?
Like, if each girl in the harem are going to have their own stories, as implied by the path system, I think there should be a hint system or something, letting you know what you have to do.
This quest/hint log doesn't have to be part of the harem/path tracker, but I feel it is or will be needed.
I guess what I'm trying to say is, don't be afraid to borrow of other games to improve your own. We all stand on the shoulders of giants.
Tell your story the way you want to, and use any tools at your disposal. The story is the main thing, the mechanics is what helps you tell it, and helps us to enjoy it.