Since I'm not foolish enough to believe I could change the course of man's history, I'll just be content changing mine and some recent.
I would make sure:
TOP ON MY LIST: no JWs called on my parents, and instead that they become the type of parents to encourage personal accomplishment and not empty time wasting on magazine sales. I would publicly air the 'hearings' when the WT df'd Ray Franz. While not innocent, I believe enough people would have seen through the veneer of spirituality they put him under. Many people's lives would change as a result.
If I couldn't, I would expose Jim Jones and that lunatic David Koresh for the frauds that they are. I would make sure the police took no violent action against the Love cult in Philly which caused the death of many children.
I would kill despots.