Going back to original question, last May we left Celebrity Apex about 7:20 (Walk Off) to train station, train to AMS, went thru security and was at terminal around 11:15. So it is doable but may be tight depending on what time you actual get off the ship and security line at AMS.
Agree with Jim and GVM's discussion on credit card usage. Another issue I did like was the wide acceptance of GPay on my Android phone just about everywhere (we didn't make it to a grocery store). Used the phone app for transit in Amsterdam.
Last thing - really really loved Amsterdam. Such a great place and met a lot of great people at the restaurants! BTW, in my opinion, Netherlands and Amsterdam has the best mass transit system.