I'm not a find of the artstyle, but that's just me, I'm a sucker for hand drown 2D. It's good enough that I could deal with it. And I love Overwatch porn, so it won't prevent me from playing the game.
I love stuff that makes people mad online, like ntr, corruption, incest, monsters. The more I see it in a game, the more I like it. It's not mandatory though, just a bonus. Make it optional or not, it's up to you. But I agree with the sentiment shared here, making it optional with either an in-game prompt or a menu setting is probably the best option. I guess it would be the same thing for gay/bi or any "controversial" content. (It felt really weird to mark gay/bi as controversial). And I think you should take it a step further and have the game say, really clearly, what it does, in a confirmation box after the first choice.
For example in your proposition, after selecting any choice there is text saying "You are going to enable/disable gay content. If you continue your character will/will not have sex with men. Do you wish to continue?" Yes/No, etc.
It may seem too much or disruptive or whatever, but when you work in programming long enough, you begin to understand how clueless and clumsy and unaware some users can be.
For stuff like body hair, I don't really know. It's true that in the majority of pornography everyone and everything is completely shaved, especially women and female characters. At that point I don't know if I really like shaved body, or if it has been forced on me from years on exposition to pornography.
Anyway. I like variety. Maybe some characters with, some characters without? Depending on what you feel would correspond to their personnality, or maybe just aesthetically.
For the MC I won't mind hair, but option C feels weird to me. It looks like he has patches of very dense hair in just a few spots, and then he is cleaned shaved everywhere else. I don't know how you can make it better. Maybe by adding different "density" of hairs in different regions? It seems to me that pubic hair should one of the more dense region on the body, and that hest hair should be more dense than harm hair. But I'm not a hairy guy myself, and I'm definitely not a connoisseur of male body hair.
And for the stats, I prefer when it's a bit on the background. I like porn games where they're lights on gameplay, and more focused on the story, branching, characters, and obviously art. I really don't like when porn games ask you to grind stats in one form or an other, it just destroys the flow. I like what Eva Kiss does with her games. Some choices improves a stat, but you know it after you selected it. And then you have a menu where you can see your current stats. So it helps with managing the branching, and I guess creating a more interesting story, but as the player you have no extra burden to remember any of it, or consciously manage it. It justs "happens" and you don't see really how it works.
Anyways, good luck my man, especially since it's your first project. Take care.