Who’s to say that the differences are “minor.” If school A offers courses equivalent to AP Physics and AP Math, and school B doesn’t, that’s a major difference, and can certainly affect someone’s admission to and performance at an elite school.
They do, and that will be a major advantage for him. But his academic background will be more important. If he’s significantly less qualified than other candidates, it won’t matter.
Nope, but it sure would help.
I’m sure that CairoCarol, being a sensible sort of person, will try to make sure that her son doesn’t pin all his hopes on MIT. But she should (and is trying) to do what she can to ensure that he has the best chance possible at getting in there, or another great school of his choice.