To book a cruise on DCL with points, you will have to pay points for at least one adult per cabin. You can pay cash for anyone else in the cabin. You can't pay part points and part cash for the same person. Also, the cash price is the one that DVC negotiated with the DCL. It may be more or less than the cash price that DCL currently offers.
You can't split a passenger, but you can pay points for two adults and then cash for the kids....you may be able to pay for one adult with points and the other cash....that I am not positive about.
Just a reminder that when you pay cash and points for a DCL booking, you pay the cash when you book, not 60 days out or anything. I booked 11 months out for our cruise end of next June, and paid cash for DS, which I had to put on a CC at that time, along with the $75 fee.
Robin M.