Was Hitler objectively bad?

[Rev. Rye]

But then again, what would have happened if, early on, he had been assassinated, and somebody actually competent managed to take over?

The world could quite possibly have been a better place. The basic idea of a single world governmnet is a good one, but Hitler decided to kill millions of people for some reason.

Way to totally miss the point of the question; the fact was, if Hitler was assassinated, many of the people in line were as anti-Semitic as Hitler was, and probably much less likely to flippantly declare wars on America and Russia while still trying to conquer Europe. If you're going to talk about Hitler, it should do you very good to actually do some research on him as opposed to just parroting half-remembered high school history lessons. I would recommend Ian Kershaw's Biography and Robert Evans' Third Reich Trilogy. Or if you don't want to go through five thousand-page volumes on the Third Reich, TVTropes has a few surprisingly informative pages on the details of the Third Reich that your history teacher was too busy trying to wrap everything up to talk about.