How would you define or asses if someone is a caring individual by nature? Do you mean she is just very nice to you during the hour? Or do you mean something else?
I would put it down to simple human instinct, prossies have the same personality traits as the general population, Most people have a gut instinct when deciding what others are like as people, yes there is a lot of acting involved on both sides but sooner or later the true person comes through be it good or bad, selfish or caring.
A caveat to my (shit) answer is if you are the kind of punter that hops from prossie to prossie then it can be quite difficult to see through the acting.
However to contradict myself again, the power of first impressions isn't to be underestimated.
I have met some very fun girls who I had a great laugh with. But I can be certain as soon as the hour is up they want me gone.
For the girl all you, me and everyone else is to them, is 6th/7th/8th guy of the day of 20 bookings.
In general i do agree with your other 2 points.
My main issue with JRC's comment was that lumping all prossies into one category is silly at best, for me that is the same as saying all coppers are bent.They are merely acting, if you had no money they would not piss on you to put out a fire.