The only DVC member discounts are at DVC resorts and that is not always available. There are no cash discounts for other resorts or DCL for DVC memebrs.
AFAIK, there are no DVC discounts on cruises. If you elect to pay cash for some of your party, the price you pay is the one DVC negotiated with the DCL. That price may be more or less than what DCL or a TA is currently charging. (Depends on how far in advance you are booking).