めっ me is used to scold little kids. It is pretty much the same as a No! Me can be used in electronic messaging in the same way. Whether it’s for comedic purposes or real scolding depends on the context. Umm yeah… sorry I don’t know why I made this.
Insta-Learn word again, and it’s so polite as well again… Anyhow, kuso can be often heard in shounen anime. It is virtually always used when something doesn’t go along plan. The translations are very very wide and have various interpretations.