I willl try and answer youur questions as I understand them.
If NCL canels your cruise yes they will refund your money.
If you miss the cruise then no refund.
As far as airline transit. I am not sure of your question. If you are asking if a flight 2 hours after docking is OK then the answer is no. Keep in mind it can be over an hour after a ship docks that they start letting passengers off the ship.
If you are asking how long from dock to airport it depends on the city and airport ?