ixon or American Imperialism, that these qualities are really only found consistently in Nova Scotia, making them the only true Yanks left.
However, if you're real question is "Will I get punched in the nose if I call someone a Yankee?" that depends on how likely they would use the term Yankee as a slur toward someone else. The best rule of thumb is not to use a term you think might be offensive unless you're ready to fight or run.