Deposits, Cancellations, and CruiseNext

I've searched the boards, and I haven't found any exact answers to these questions. If there are posts that answer the following, please point me in that direction!

I purchased CruiseNext certificates for the first time this month. I am now seeing sailings that I'd love to lock in the prices for, but am not 100% committed to. Can I make a reservation, pay the $50 deposit (that's required right now), and apply CruiseNext certificates when I make final payment? Also, if I make the reservation and end up canceling with more than 120 prior to sail, will I receive my $50 deposit back, or will it be forfeit?

Thanks in advance!

You will get the $50.00 back. Sorry, I don't know about the Cruise Next cert. Don't forget, it's $50.00 PP.

I had to use my Cruise Next certificates as the deposit on a cruise, I could not add them to a cruise already booked.