Earlier quoted context omitted.
Is insulting a female inherently sexist? I wouldn't call someone a sexist if they called me a d ck or a son of a b tch. Obviously the response here is sexist, but calling somebody bad names is not sexist, regardless of their gender.
IMHO, sexualized epithets are sexual. It's more productive not to muddy the waters though: it's not like there are only a handful of ways to insult someone.
English is definitely one of the least sexualizing languages of the Romance Languages. In French or Spanish, everything would be attached to a gender, but that doesn't mean that the words define the gender themselves. Nobody in Spain thinks that chairs are 'where women belong' or anything like that.