Hate to point it out, but DPS is the correct term for FFXIV. Check your Duty Finder. Check Yoshi P on the subject.

As for the other stuff, sorry to say, no one has rules on what terminology should be used. I guess you can make a FC with friends who use the same terms as you do. Otherwise, you have no hope of fixing what people say and you're doomed to be annoyed for a very long time.