Re: elevators:
My husband has often said, "Wait! let them come out, first!" to the folks waiting for an elevator, as they rush to the one with the door starting to open. Rude! What's the hurry?!
A good tip on cruises generally, don't touch the handrails unless you really need to!
If you are on a ship with the glass blowing class, go and watch, it's very cool. Going to try it out for myself in January.