>trans women and regular women

Side note observation, "regular women" can be perceived as insensitive to trans women. I'm not sure what the best term to use is either though, when differentiating between trans and non-trans of the same gender. "Biological women"?

The term that is generally accepted is "cis" or "cisgendered"

The distinguishing term is cis (born that way) vs trans (hormones, ops etc). Hence I'm a cis male because I was born as one. Had I become one I'd be a trans male. I think that's right.

> "regular women" can be perceived as insensitive to trans women

I know a few trans (mostly t-women) and insensitivity/nastiness is AFAIK not so tied to gender.

'non-trans' works fine and is clearer to most people. 'cisgendered' is also correct, but it has political connotations, eg 'cishet scum'. WikiPedia has some good references: https://en.wikipedia.org/wiki/Cisgender

I think the insulting part of "cishet scum" is "scum." I definitely see "cis" and occasionally "cishet" as entirely denotative self-identifications in spaces where it's relevant and trans and non-heterosexual folks are at least more visibly represented than in the world at large, and it's neither positive nor negative, it's just what one is.

The phrase "male chauvinist" doesn't mean there's an intrinsic negative connotation in calling someone "male," nor does the phrase "nasty woman" mean it's intrinsically negative to call someone a "woman." (Of course, both terms might be used as insults in context / with tone / etc.)

Most people consider 'nasty woman' and 'male chauvinist' clearly based on sex - otherwise you'd just call them nasty or sexist.