You might modify the clue for most college football championships to clarify that only major FBS schools are counted. In fact, the answer to the second question is the correct answer to this one also (18 versus 17) if all championships since 1869 are counted.
Agreed on both these points. California-Berkeley, or Cal-Berkeley, or California, or just Cal. "Berkeley" is also used colloquially, but giving it a B makes it an outlier on this list.
Really shocked that Oberlin, a tiny liberal arts school not known for really for anything other than being the first college to admit women that is still in existence is not that far behind Duke and University of Chicago. I get that the Duke question is fairly obscure but there aren't a whole lot of well known schools beginning with a D. They don't pop into the national consciousness from major college sports nor ground breaking research. Never had a major piece of popular culture associated with it or historic event. Sorry if if think I am dogging the college but it's remarkable that so many people got it in comparison to other better known schools.
I don't know how influential this is but it's a convenient crossword answer and shows up probably disproportionately; and usually clued with that fact about it.