Personally, I found the Fatal Attraction parody more dark and creepy than overtly sexist. Perhaps because it was referring specifically to a movie (though the movie itself, one could point out, was quite sexist, so...). Yeah, sexist-ish.
I think that in general, calling Melania anything at all seeks to shame her for being a model is complete fucking bullshit and sexist, yes. Though I will say that pointing out the hypocrisy of the right freaking out about Michelle Obama baring her arms vs. Melania's posing for nude photo shoots is completely reasonable. But Melania's modeling choices are her own, and I don't see any point to calling attention to them as some sort of condemnation of her per se. (And yes, calling her a hooker is sexist, not even a question that calling someone a hooker is sexist unless they actually were a hooker).
I'm not comfortable with sexism on either side. But of course, it's much easier for someone to point out the sexism that happens on the other end of the spectrum from where they sit (for example, if you're on the right, pointing out the sexism of calling Melania a hooker), than it is to acknowledge the sexism on their own end (the absolute over the top sexism directed toward Hillary by many on the right during her presidential run).
So:
"Is there a frenzy of sexist poop throwing at influential female figures on the right?"
FTFY.
And yes.