I think what most people can agree to, though you can analyse it as much as you want to and it really doesn't bother a lot of people, the word is still designed to be an insult, or at least that is what the word means to most people. It's not a particularly attractive word full stop, it doesn't sound attractive. It is a word that is commonly used as an insult, it can be used as a form of endearment and for all sorts of reasons, but it is rarely a word described for what it actually means, so regardless of what the dictionary says (because really why does the dictionary dictate a meaning of a word if people are using it more for something other than the dictionary meaning?), to most people it's a rude word designed to slut shame a woman and mark her as something dirty. Now in sexual play and stuff this can be fun and I'm not totally opposed to the word, but I think in general it's pretty safe to say that it's an insulting word. One that you could only say to someone close to you without it being seen as inappropriate or an insult. The meaning of the word is pretty clear.
Like Aella said, it's the intent behind words that make them insulting, but I think if someone tries using the word "whore" casually to someone they don't know very well and aren't meaning to insult them then they really need to get their head checked. Words are there to show our intent, people aren't mind readers, so if someone casually called someone a whore, even if they meant something else, the word they used still holds power. People aren't mind readers, we can't always tell the intent and do rely on language to communicate our feelings.
As a rule, though many people really aren't all that fussed about it, probably best not to throw the word around casually. Though I appreciate your point Crumb, and maybe you're right by a dictionary reference, but you did just call all camgirls whores. Personally I AM insulted by that and don't really like someone suggesting it. By those standards a stripper, a glamour model or a burlesque dancer would also all be "whores". They all perform different forms of sexual acts/acts aimed to give men sexual gratification. I don't think I'm a whore, and though I cam and I make videos and do shows, so on the members side perhaps it seems like sex, on my side it isn't anything like having sex. They may be acts of a sexual nature, but they are not sex acts. In my opinion for them to be sex acts there has to be physical touching involved. You can go on the cyber whore angle, which is much more true to the case. Your dictionary reference is broad and could refer to a lot of things. You can interpret it in very different ways, and though it doesn't say real life sex acts, I think it is probably meant in such a way (especially as paid cyber sex is a fairly recent movement).