@DBZ_universe: Peter Griffin said it best: "Just try not to look directly into it."
Saying Goku can't planet bust is stupid. Saying he can't control his ki blasts is beyond ridiculous. There are several examples of the cast of dragonball controlling their ki blasts. Piccolo's hellzone grenade is nothing but control. Goku can bend the kamehameha at will and has been able to since he was a kid. Hell he can even fire one through his feet for the sole purpose of just speedblitzing his opponent. Vegeta calculated the angle of his Final Flash perfectly to avoid destroying the earth when he fired it at Cell and the list just goes on and on. All you have to do is just read the manga to know this basic fact.