I do think that a well worded letter to Corporate is appropriate.
It does make it a little more difficult if there was not a complaint on file from the ship, because their first thought is going to be "why didn't they say anything?"
However, I can understand that each incident alone may not have been enough to complain about...but you put them all together and it adds up.
Sadly, "bus riders" are usually the biggest disappointment with Carnival. And you never know when you are going to have them as your neighbors.
In all our cruises, I too have had one that was just off (on the Holiday years ago)....
Dave probably remembers we writing about it....so you are not alone. It happens.
If you want to write a letter to Gerry Cahill, I would start off with all the good parts of the cruise and then say "however, the reason for my letter is ..." and then give him the bullet points.
The address is:
Carnival Cruise Lines
3655 NW 87 Avenue
Miami, Fl 33178-2428
Hope your next one is back to the "good ole days" !!!