1) as I understand it, all Google Scholar does it have a search engine which contains nothing but academic papers. I'm not sure how it calculates page rank but I don't believe it has anything to do with cross citation. I think of Google scholar as almost a distraction from something more useful. Web of science is a better start, although I would certainly make it more cross disciplinary.... I wouldn't limit it to scholarly papers; I would include web pages, blogs that focus on the scholarly (ie. catalogablog would count), anything on the open web that would be likely to be useful to an academic researcher. And I would calculate weighted rankings specifically by how frequently they referred to one another (adjusted for all kinds of fine details), but in no way by how frequently they were referred to by documents outside of the scholarly pool. Does Public Library of Science perform any kind of weighted rankings? I suppose I should go look, but it's two in the morning.

2) Ah, I wondered. But I didn't want to say that, because of course, as a librarian and computer scientist, I value open access in an inherently judgmental way, and perforce to me, the statement "some fields don't value open access" is the same as saying "some fields are evil bad and wrong!" So I tried to come up with some justification for why they might act differently from those in my information cultures without being Bad Secretive People. Which only reveals my own biases and makes me look ignorant. :)