1. No, but it can probably be dug out of Google Analytics. I'll let the experiment finish first.
2. I'm not sure how exactly it is calculated. On what is apparently an official blog, the author says in a comment: "We do correct for multiple comparisons using the Bonferroni adjustment. We've looked into others, but they don't offer that much more improvement over this conservative approach."

Yes, I'm finding the result odd. I really did expect some sort of inverted V result where a medium sized max-width was "just right". Unfortunately, with a doubling of the sample size, the ordering remains pretty much the same: 1300px beats everyone, with 900px passing 1200px and 1100px. I'm starting to wonder if maybe there's 2 distinct populations of users - maybe desktop users with wide screens and then smartphones? Doesn't quite make sense since the phones should be setting their own width but...