I believe that you cannot use points for categories 1,2 or 3. In any case, you are talking a boatload of points! We just cruised on points for 2 adults and 2 children and paid cash for my youngest since we needed a cat. 4--our BWV points are gone through 2004, and most of our VWL as well.
If you decide to use points rest assured that the category 4 rooms are very nice.
Robin M.