Movie 8 is the first one with Broly; I was unaware of anything related to acid, though. I'm mostly just looking for the uncut DVD so I can watch it in Japanese.

And as far as I know, Dan Dan was the ending theme for DragonBall or DBZ. I've only heared it at the end of the "Path to Being the Strongest" DVD--the movie made to celebrate ten years since Dragonball was released.

And I have no idea what the Japanese opening theme for DBGT was.

EDIT: I searched the internet, and appearantly Dan Dan was used as the theme for DBGT.