In my opinion it is simple common sense to use context, tone, and other clues to ascertain when a person is attempting to be hostile or insulting, and it should be very clear indeed when they are simply trying to be friendly. Regardless of exact specific words used. So to go around just waiting for a chance to get your back up about something that someone used as an obvious attempt at casual friendliness, is snobby and pretentious behavior.
I respect more the way Ani describes the matter as being understood among a certain community of individuals who settled a specific region and share a history. To go into a place not knowing custom, and blunder and make a fool of yourself...well you learn sooner or later, now don't you?
But the English language has over time, and especially as it's been used on different continents, evolved. Many, MANY words no longer mean what their roots meant. And so to say that there is an absolute truth to your understanding of a word, because the root definition is thus or so...that's absurd. Language is a living thing, and it changes over time. I guarantee that there are words that each and every one of us uses in contradiction to their historical meaning. That argument is invalid. The argument regarding regional, historical, and cultural meaning is far more valid.
But regardless of all that, I find my life to be much more positive and enjoyable when I go about not looking for reasons to get offended, ESPECIALLY when it is OBVIOUS that the speaker means no offense. And if I suspected that someone had a whole host of rules I didn't know that would get them all in a huff and a snuff at me for reasons I didn't understand, then I wouldn't invite them to dinner at my house, either.
So you can keep your chitlins and I shall keep my Kraft macaroni and cheese, thankyouverymuch.