@bloodynights: "quotes are often times completely misleading" That's true if someone focusing more on the problems and less on the answers. You can find answer for every question, that related with the series.
Gotenks is a character like that with reason. It wasn't a quote you mentioned, but it was proven to be wrong(his opinion that he can defeat buu), so what's misleading about it, feat-wise? He couldn't beat him and Piccolo warmed him too. He was an annoying immature kid. That's the purpose of his character.