No. If you book a cruise thru DVC, at least one passenger needs to be paid for using points. If you opt to pay cash for any other passengers, it's at a pre-negotiated rate. Any cash portion is due in full at the time the reservation is made.
As for member cash resort discounts, those when available are only for DVC resorts.
If you book directly with DCL, just being DVC doesn't get you a discount. Recently, DCL has offered a couple of specials to DVC Members to fill cruises that were sailing within a couple of months.