I've been in the middle of the north Atlantic, at night, on a ship with a fire happening. It was the Navy and we were close to going to General Quarters because of the fire. I do know everyone was awakened and told to dress and stand by. Thankfully we got the fire under control and put it out (electrical fire).
My issue is Carnival has opened this up to individual interpretation, and at least in some passengers minds they could comply with the list only to have things taken away at embarkation. Some people need a cut-and-dried list to feel comfortable. Now there are many things which "may" be okay. I can understand having latitude, but I think they went too far with the vague terms.
Realistically I think Carnival will not be harsh about it. However the port screening people don't work for Carnival. There are a lot of Barney Fife's out there.
Vanessa plans to bring a curling iron on our July cruise aboard the Elation. The Mobile port staff is wonderful and I don't anticipate a problem.
Of course, since I wield ruthless power as a cruise journalist if any problems develop I'll expound on them here!