Alright Lion, I'll try to answer your questions from my perspective.
#1 How important is diversity?
I think diversity is very important. Right now IMO there are not enough URMs in the legal field. Therefore, do believe that a *small* amount of preferential treatment for URMs in application decisions is appropriate.
#2 What do numbers really mean?
I think numbers are good general measures of an applicant's ability and potential, but should not be used as absolute measures of a person's ability to succeed in school and in life.
There are many factors that can drag a person's grades and test scores below that person's "potential" and I think it's appropriate for a law school to consider those factors.
I'm not saying anyone should get into Yale with a 2.7/150 ... but I don't think someone with a 165 LSAT is automatically more qualified than someone with a 162.
#3 I think we need to increase the numbers of minorities AND disadvantaged people attending law school. I don't think that makes "the group" more important than "the individual."
#4 I see AA the way you do -- if two are more or less equally qualified, give the preference to the "diversity" candidate.
I don't see AA as giving HUGE preferences, but modest preferences. And I don't see anything wrong with that.