It seemed that your profile is stellar. You could target top 10(I am assuming that your extra-curri etc. are also stellar). Quitting PhD is not an issue, as long as you haven't spent more than 2 years in it. Adcom is intelligent enough to understand that it takes one 1-2 years to understand what a PhD really is. My personal opinion is that you cannot tell the adcom that your PhD major is not good, because PhDs are the same across all majors(I could be wrong with this point, but I believe many people with PhD degrees will agree with me). The real reason is that you quit PhD not because the major is not good, but because the PhD career path is orthogonal to the business career which you are extremely interested in. You government WE is defnitely a positive factor for the application. As to the GMAT, most of the b-schools will look at the highest score. For other problems, you can refer to the post on this borad. Help this helps and good luck!