@Grativity The essay in the link you provided probably deserves a score no higher than 8, IMO. Unfortunately, essay score and length are too highly correlated on the SAT, but that does not necessarily mean you should get a higher score for a longer essay.
I have to agree with what @bodangles said, except for the part about making up facts. SAT essay graders don’t check your factual claims for accuracy (in fact, I don’t think they’re allowed to). But don’t put BS such as “It is widely known that Barack Obama invented calculus” or things along those lines.
Definitely. Your second paragraph contained too much background information, and very little of it was used to prove your point.