The Last Sovereign is an outstanding game with excellent writing.

I think you'll like it. The female characters have a lot of agency and their own reasons for being where they are; it's not like the protagonist forces them to fuck him or anything like that. They're not in the game just to provide material for sex scenes. To me, TLS is certainly not a sexist game, though I understand that the definition of "sexist" varies widely between people.

Now, there are one or two scenes where rape is present. However, there are easy and obvious ways to avoid those scenes.

Also, there are points in the plot where the... depth, shall I say, of two characters can be eroded. But as with the inclusion of rape, there are clearly marked points for you to avoid them. In fact, all these decisions are made via a yes/no menu.

Finally, there is a point in the plot with which some people were uncomfortable. However, it's not listed in your post; if it were, I wouldn't be recommending this game to you.

I still believe it warrants mentioning, but I'm afraid I can't describe it very well without plot spoilers:

The protagonist enters a sexual relationship with his adult adopted daughter. As with all the other relationships in this game, it is completely consensual; the daughter initiated it, and the protagonist took a significant amount of time to consider the ethics of the relationship before consenting to it. I'd say the game goes out of its way to make it clear that the relationship is between two consenting adults with the same level of agency / power... But the level and amount of writing about it is par for the course in this game.

End spoilers