Yes, you're exactly right on the first point. I'm still keeping the femdom light; this is just the introduction for the game. But as we delve deeper into the story, the player will be able to choose how hardcore they want to go.As mentioned clearly in the OP that it's a femdom themed although I feel at few instance Asmodeus held himself maybe to keep the femdom bit more light as in the reward ofc sexual is too easy for the MC you gotta boost those depravity number before you let MC have the reward.
Coming to the characters I think any good female dominatrix need to look bit cold and calculating, your avg cute models doesn't cut it. While it's true to some characters of this game but they still look bit friendly which is in contrast to the requirement. If I may give the example of some other game it would be the milf character from Estate dominate or even Marge from MMC, both model nails the dominatrix look which is exact opposite to the cute and friendly looking characters from Karlsson's gambit it doesn't do justice to the story it looks forced and bland.
Since Asmodeus is also the writer of MMC and the boss roleplay with zip tie was clearly my fav scene I can say that my man knows how to do it just right without overdoing or undercutting anything.
Now on the second point, about the look of the dominas; I like to create contrasting characteristics. For example (unrelated to the game), a cute innocent looking girl that is evil as fuck, an ugly looking character that expresses the most beautiful feelings. This is not only for shock value, but that's life. It's the essence of the meaning "you can't judge a book by its cover".
And that also helps with the narrative I'm creating; that you can't figure out what a character is like just by their appearance. You need to notice, how they act and what are they're saying. If a girl looks like a bimbo, doesn't mean she's a bimbo. She's just dresses like a bimbo. You need to know her to understand what she's like.