I am sure you are getting excited, now the countdown is only 10 days out ---
Q.1: Although they will not kick you out of the dining room, I think you would feel more appropriately dressed in dockers as opposed to windpants. Actually a nice pair of dress jeans would be preferable to windpants.
Q.2:Milk is free around the clock, but not always available. You can always get it if seated in the main dining room, or order from room service, and it is always at the breakfast buffet, but after that it is not always easy to find. Milk was (is) my daughter's beverage of choice also - so I used to take a couple of cartons from the breakfast buffet and put in the cabin fridge.
Q.3: Theft - Sure there is always the possiblity of theft when there are that many people in one place. BUT, in all of my years of cruising I have never had anything (nor have any of my friends) stolen at the pool - no matter how long my sandals and bag sat unwatched while I was in the Jacuzzi.
Q.4: I can't help you with this one. Sorry -