I will focus on #1 as I think it is absurd, along with their rankings of colleges, and a close examination of the factors used to rank them generally reveal enormous flaws in the methodology.
The first and most important factor they used was a look at test scores, something that almost everyone who has studied it closely suggests are more often linked to background and socioeconomics than anything else. US News controlled for peer institutions and tried to only compare high schools with similar socio-economic breakdowns, but there are so many factors involved here it would be impossible to do a comprehensive review with a thorough look at all of them.
Once past the first two factors, the ranking was based in many ways on participation in AP classes. This is a number that can be affected by the style of the teachers, th emphasis on AP classes themselves, the expectations about grades for the students in the school and so many other things. If the goal of a school was to have all students participate in AP or IB classes, they could simply mandate that everyone take them. I don't even think that is necessarily a bad idea. But because that also depends to some extent on funding, willingness to pay for teacher training, etc., it is somewhat faulty when it comes to really determining which are the "best" schools.