Assuming that what Nigel Farage said has been reported accurately his views appear to be no different to that of Adam Walker and his mob otherwise known as the BNP. My wife's parents live on the edge of Nelson and have been racially abused by members of the BNP in the past, causing great upset and distress.
Very sad to hear that

I can imaging being at the receiving end of such abuse would be extremely distressful.
As a consequence I consider them and the rest of their party to be vile human beings. I would be interested to know whether in this instance you believe that I'm making a "crude insult" and whether you would make a similar "crude insult" if your own family were being racially attacked.
I think I would always consider 'vile human being' to be a crude insult. If I had myself been subject to the kind of abuse you've described, I might well use it myself in the heat of the moment, but I'd probably regret having done so later. I would suggest there are two important distinctions to be made here:
Firstly, the distinction between actions and a person. I don't see any problem in describing the
action of racially abusing someone as vile. But to go on from that to describe the
person as 'vile' seems wrong to me. When you start viewing people in that kind of way, then I would suggest that you're falling into the very same trap that leads to racial abuse and so many other problems in the first place. When you describe a person (as opposed to an action) as vile, you are implying that there is something less worthy about that person. Which is of course exactly what leads to racism. How many wars have started, and how much persecution has happened throughout history because one group of people became convinced that another group of people were in some way less worthy as human beings? Closer to home, how much hatred gets stirred up because tabloid papers routinely describe people they don't like using that kind of language? So no, I would urge you not to fall into that trap.
I personally want to see a World where people always treat each other with respect and consideration, and where everyone is valued as a human being. That's after all the fundamental reason why I'm in the Labour Party. And I'm guessing you would like to see the same thing. I know that's very idealistic and is not going to happen any time soon, but it's the direction I want to see society move in. But you're certainly not going to get there if you start thinking of some human beings as 'vile' - that's the kind of thinking that moves you in the opposite direction - towards conflict and a world where people are routinely marginalized and persecuted. (And ironically is exactly BNP-type thinking!). Condemn the action, not the person.
Secondly, the distinction between views and actions is important. Nigel Farage clearly holds opinions that you and I find unpleasant, but I'm not aware of him ever having been reported as directly racially abusing any individuals. Because of that, I don't think your comparison of his comments with the atrocious actions of members of the BNP that you've mentioned is entirely fair. I'm guessing the comments you are referring to are
these (The Independent)
NigelFarage said:
I'm commenting on the state of modern Britain, post mass immigration. It means effectively that in some of these seats where people don't speak English and they sign up to postal votes, effectively the electoral process is now dead.
You may or may not agree with that comment (and I personally I do have some suspicion that it's motivated in part by sour grapes), but suggesting that there could be issues with people who don't speak English being able to understand what they are voting for seems a very long way from racially abusing people. (Or did Farage say something else that I've missed?)