"'Faggot' is a well-known insult, that everyone finds offensive when someone they don't like calls them one."
So well known that is completely escaped the authorities on the English language at the Oxford English Dictionary.
Why do you avoid the citations to American dictionaries already given?
Don't know, or care, about the dictionary definition. The street definition is clear.
If someone calls me or you a 'faggot', we're insulted.
If you're on record as being okay with calling others 'faggot', then so be it. I think it's wrong to call others 'faggot'.