As both a teacher and a player I can tell you that if you just relax, play what you know, do it to the best of your ability, be honest, and really want to learn...the prof's will see you for what you are. ... someone that wants to excel at music.
As an undergrad I freaked out about auditions.
As a grad student I just figured that I knew what I knew and that was going to have to be good enough to get in. Then once I was in, I had to work really hard to bring my self up to the standards of the school/teacher.
As a post grad, looking at PhD/DMA level schools in composition/arranging in classical/film scoring/jazz/vocal jazz I am getting my CV and reel together for sharing with the different "A" schools. (At this level it has to be an A school) If they don't think I will fit then I will move on to the next one.
As a teacher, my students freak out (I teach high school) and I keep telling them...I am listening for what you have, not what you think I want to hear. I watch them interact with their peers, I listen to how they talk amongst themselves.
For me, it is more about raw talent, integrity, hard work, and a willingness to learn (a paper person) than it is about how cool or what slick things you can do.
Hope this helps those of you in the grinder.
oh...also...when I was an undergrad...the prof told me that his job, in the first year or so, was to wash out those that could not hold their own. So, if you feel that they are after you...you might be right. And it probably isn't personal. Remember that their name (the prof's and the school's) goes where you go. You, by virtue of going there, represent the school.
So, learn your 48 scales (12: major, nat minor, harmonic minor, melodic minor), sightread everything you can get your hands on, learn music fundamentals, be someone others would be happy to work with.
IMHO