In general, when the word "whore" is used by outsiders (that is, those not working in the sex industry), it is with derogatory intent. I should have been more specific and said "strangers." Obviously, it's about context--if close friends were using that word, I know they're not being derogatory. It's entirely different when coming out of the mouth of a stranger who has just met me and thinks it's okay because I use the word. It's not.
I look at it in much the same way the "N" word is used. Unless you're black, you do not have the right to be throwing that word around.
In both contexts, unless you are black or a whore, you don't know what it's like to have that word used to demean you, and you shouldn't use it just because you can.
I'm all for free speech, but I'm still going to think you're rude if you're anyone but close friends or other sex workers.
Words are never *just* words: they have power. If you want to cast a spell, that's all you have to do--SPELL.