1) When your professor says, "My opinion doesn't matter - I want to hear your ideas on the topic," DON'T BELIEVE THEM! Your professor is LYING TO YOU. Of course his idea matters. It's all that matters! Think about it; how is he supposed to like a paper that insults the supremacy of his idea and the academic mastery that he has most certainly achieved?
2) There is no such thing as too much detail. If you want to succeed in college, it's in your best interest not to make clear concise points when supporting your argument. Forget the general population's desire for information to be presented short, sweet, and to the point. Once you graduate high school and you're out in the "real world," it's practically considered a sport to see how many (pointlessly) relevant details you can toss into your paper.
Happy hunting.