"I want to write an article about terms for people (particularly negative ones) that are prevalent in Britain but not in North America. Any suggestions aside from "yob," "laddish" and wanker?"
At last count, there were approximately 3,428 webpages doing exactly what you describe.
They are either written by Brits, and hence contain words/expressions that are already well known in the US (and were probably invented there), or by Yanks, and hence contain incorrect definitions of words/expressions, or examples that fell out of use at least 53 years ago.
And I'm qualified to make the above statement as I am neither a Brit nor a Yank.