I only leave less than 5 stars reviews to scammers or insulting buyers. Otherwise, I forgive buyers who cause small troubles considering no one is perfect.
When buyers call me Hi man, Hi mate. It puts me off to work with them. Obviously, I am a man but you do not need to tell me that everytime to buy something from me.
And for mate, I am not your husband or friend why would you call me that?
Do not worry and just respond to the review in a professional manner. One negative review will affect your gig rankings for sometime (one week or more).
Yes, I have. There is nothing wrong in giving buyers 1-star negative review (should be honest though). It will free Fiverr from scammers and serve as a warning for other sellers