Originally posted by jasofisc
the only thing I want to comment on is the kid buu going from planet to planet blowing him self up when he would destroy galaxies. that was never ever stated. Goku therorized that's what kid buu was going to do to earth when they were fighting him. more superman side bias. reading into what you want from the animi and mangaoh and as for your questions at the end of your rant it's because DBZ characters can control the energy they put forth. (I know it's impossible but that's dbz for you and the only way things like that can make any since at all.)
In the anime Buu IT's from planet to planet blowing them up before teleporting to Other World to fight Krillen and the rest then going to Kaioshin's planet. In the manga he just blows up Earth then reforms and then goes to Kaioshin's planets.
Also sure they can control how much energy they put out but Vegeta went all out, Gohan's blast was full power, Super Buu's attack was full power. Yet these blast didn't destroy the galaxy just flew off into space. It even show's Super Buu's attack explode, not sure about Vegeta's. Then the fact that Majin Vegeta's explosion was full power energy in all directions yet Earth still stood.
At the least if Vegeta, at SSJ2 used a full out attack and he could destroy the world effortlessly then why didn't him blowing himself up to kill Buu destroy a lot more. I'm more inclined to believe that the weaker attacks that destroyed the planets had more with doing like what Freeza did on Namek.