The travel skills required may vary with location, so check with me on that if you feel that you are an especially weak skier or boarder. You do not need to be an expert, just able to travel reliably in mountain terrain with or without grace or good style.
Enrollment is dependent on the approval of the instructor.
I have had poor experience with people bypassing a basic class thinking that they have equivalent experience. I may suggest you take one again as a refresher. There are no hard requirements - everyone's background is different and we'll discuss yours as it pertains to this course. In an advanced course it is essential to be able to inspect, compare, and contrast snow profiles with significant differences. Students are not expected to be expert skiers, but efficient travel skills are required.