Thanks for the reply! This is a pretty well thought-out response, which I appreciate, because I was a bit harsh in my review. You have clearly put a lot of effort into this project, which I respect. Admittedly, I have only played through a few hours of content, so I guess I haven't really gotten to any of the newer anti-slavery content you describe.
Regarding the pee scene, I believe it was one of the park scenes from exploring the town. Not technically unavoidable in that you don't have to trigger it, but there's no indication beforehand that it's going to involve urination.
As far as the slavery content: my concern is that early on, the PC's apparent indifference doesn't come across as a result of a natural consequence of living in a world where slavery is common or permitted (which would make complete sense if he had grown up in the country), but as a weird non-reaction to something that should be foreign and probably disturbing to him. You'd be the lore expert, not me, but I believe it's mentioned that slavery isn't practiced where he came from. And given that it's pretty early in the story that the PC is able to encounter the consequences of slavery and anti-elvish racism in this new setting he finds himself in. You compare the setting to colonial America. It was often foreigners, like English or French visitors or immigrants after the practice of slavery had been abolished in their homelands, or northerners who were not immersed in the slave culture, who would go to the American South and become horrified and radicalized against slavery. Anyway, insofar as you have added more content where the PC becomes anti-slavery, I'm glad to hear about it, but I really do think that there should be more ability to express such an opinion early on.
This is a bit disconnected, but I'd like to offer you a bit of praise for something I liked: early on, when Lin asked what she should call me, I just typed in the name I had given my character, and she specifically acknowledged that I was asking her to just call me by my name and not "Master" or something. This was good for immersion, and I'm glad you specifically implemented a check for if the player uses the name given to the PC.
Anyway, regarding the scene with Vanessa criticizing the PC, I think that by the point in the story at which it occurs (or at least by the point at which I encountered it), the PC has not yet earned his anti-slavery bona fides and thus does not deserve for the scene to be resolved in his favor with Vanessa being told off. The most I could say for him at that point was that he's been nice to Lin, has not forced her to do anything she doesn't want to, and has not made her wear a collar. You say doesn't treat Lin like a slave; I think whether that's true depends on whether he's paying her for her labor, and I don't think that's explicitly addressed in the game at that point. My point here is that this creates a bizarre thematic tension: the game keeps showing us that slavery is bad, but in this moment the PC, who up to this point has not really done anything to indicate feelings on the matter beyond perhaps mild disapproval, seems to be held up as a good person not just despite owning a slave, but actually good in his capacity as a slaveowner. If his response to Vanessa was to express that he, too, is anti-slavery, that he only owns a slave due to circumstance, and that he treats Lin as a free individual to the fullest possible extent, this would be thematically coherent, but this can't really happen, because by this point he hasn't really been shown to have these convictions or to take action on them. On the other hand, if the situation were to resolve with Vanessa's words actually affecting him and making him think twice about his place in this society, this would also be thematically coherent and would probably be a pretty powerful moment. As it stands, though, the scene gives off the impression that Vanessa is wrong to criticize PC because, although slavery is bad in general, PC is a nice slaver, as though the real problem with institutionalized ownership of people is that most people don't do it kindly enough.
Like I said above, though, I'm glad to hear that the PC is able to take a more explicit anti-slavery stance later on in the story. Knowing this, I will likely continue playing so that I can see some of this content. I was getting a bit frustrated with PC's apparent apathy.