I hope V is not taken as representative of her place of upbringing. As in Houston, Londoners are a very diverse breed.
WT is well known to be a term of severe abuse in UK. The words may not be censored, but the overall intent is very clear. It is never meant as a term of endearment, and is likely to cause a physical cat fight if used. One would be very wary of using it against a woman if her man was within earshot.
Probably the most it would be used would be between teenage schoolgirls.
Britain is not, in contrast to popular conception, driven by class, but that does not mean that accusing somebody of being lowest class is not an insult.
Almost as much of an insult as calling somebody an upper class snob.
WT is maybe the equivalent of 'ghetto bitch', which is always a term of abuse and snobbery.
So, no getting away from the fact that V knew the term was inflammatory and there is no problem of translation across the atlantic.
Thought I would clear that up. There is a certain type of Britain abroad for which many of the British population feel a deep shame.
Not to say I still think some of the attacks on V were over the top.