This is a slang, foul-mouthed way to talk. It just means, "don't be a jerk". However, it is dirty talk. A lot of dirty talk seems to refer to a person's private anatomy, and talk like this is not used by intelligent, refined, people of good character.

In this context, it means if you are rude to people while giving criticisms, they will not listen to your advice. You are wasting your time giving advice if you are rude. Be nice and they will listen to suggestions. It often means, you are being a jerk. Quit it.

Hi - It means the same as "don't be a jerk," or "don't be a fool," but is more rude and informal. You might say it to your friend as a joke but you probably should not say it to your dad!