I think you need to understand one thing -- if you don't produce a credit/debit card or cash (or travelers checks) you will not be getting on the ship. That is each person, not each cabin. If there are 2 of you, each person has to have a card or cash to secure an onboard account. You can be assured that NCL is going to get the $10 per person per day charge.
From what I have heard from other people, if you give a debit card the cruiseline puts a hold on your checking account for a certain amount of money so that they get theirs. If you don't have enough in your checking account you could end up with checks coming in with insufficient funds.
When it comes to the money, you better believe that the cruiselines know how to get the money. You will not get over on them.
newmexicoNita, I will confess to being the first person you find to have paid brochure price for a cruise. It was our first cruise and we knew nothing. Now we book our own online -- and there is NO way we will pay anything close to brochure price.