Hmmm, I do not want to be called Ma'am I am only 27!!!
I also don't want to be called Ms. "FirstName" I notice this seems to be a Southern thing. I know its good manners but it reminds me of slavery.
As far as slang goes, someone I don't know calling me out my name no way, however my best friend and I call each other the "b" word, we use it and I know it probably would trip some people out but it stems back from college (hey that was 10 years ago) and we have never shaked it.