Vox, I apologize. I posted while you were responding so you've already answered some of the questions I raised again.
I completely agree with you that the misuse of the term is so widespread that it is difficult to even come up with a solid definition for what a whore/slut/etc is. That is precisely why I think people should keep their traps shut before they sling out that word to tear someone down. Be direct. Just come right out and say exactly what it is you mean instead of hiding behind this all-inclusive, misogynist term. "She sleeps with a lot of men." "She falls for the oldest lines in the book." Etc.