Soft Whisper
This seems to be your first game, so I recommend you do a Kinetic VN, it's so common to see games being abandoned because the DEV can't handle it, I think your focus should be on completing your game, that's a
trophy here at F95.
Your game is a harem, choices and variables are not important here, in the end the MC will have them all, and I believe that most players play with mods, so basically the story will be linear, your game being linear or not.
From your description of the girls, I believe, and hope, that there are no new girls in the harem, what I would like to see is the journey that will take these girls to your harem, that is more interesting than adding more and more girls without much of a story just to make up the numbers.
There are games where the player needs to make choices, but not in a harem game, especially not in a harem game with few girls, and with girls with similar appearances, which is your case here where the girls differ more in personality than appearance.
As it is your first game, I recommend that you don't overcomplicate it, focus on completing your game, this will solidify your brand, and what you gain during the development of this game, you can invest in more hardware, so you can make a more complicated game next time.
In a visual novel, the journey is more important than the destination.