Eh, I don't see why the Empire would want to destroy their own planet. And I don't think there's anything particularly wrong with the explosion. It looks cool and the Death Star is huge enough that I will believe it. Though, being used to PAL speedup it almost looks a bit too slow when seen in normal speed. And I don't mind the shockwave either really, Star Wars space doesn't seem to adhere to any kind of physics.

Now if anything should be done to that part it's showing whatever happened to the rest of the imperial fleet. One shot it's there the next it's gone and everything is fine and dandy for no reason.

Also, who's Jerjerrod?! I don't recall any such character from the movie.