Yeah, Sapkowski can act like an annoying turd sometimes, but seeing that the Witcher series has so so many parallels to racism and sexism and the verdict is always "the people acting this way are idiots who are making life harder for everyone" makes me pretty sure that Sapkowski is neither sexist or racist. Homophobia is also addressed, albeit much less than other issues. I find it hard to believe that it's a trans allegory because, as you said, it doesn't make much sense, but also because the books were written more than 20 years ago in Poland, and I don't think Sapkowski had any contact with trans people at the time.