Kathryn,
It sounds like you have some good direction for your situation and have thought through what it might look like for you to have an alumni program. I certainly agree that it is good to decide the 'direction' of your program before you begin. It might be helpful to include some of your graduates, staff, administration, even current students, to come together and help you with that process. This group might even turn out to be your future advisory board?
June Gudeman