Soda cards entitled you to soda at anytime of the day or night from the bar or from bar service. I do not think room service is included.
Yes there are planned activities for kids from 2 to 18 every night with the older teens usually getting the disco every night between 9 and 10:30 or 11PM.
Unless you are 6'6" and or grossly obese than you will fit in the bunk beds nicely. Carnival has the largest standard cabns of any cruise line with the rooms being 182 sq ft.
Handheld steamers are fine and very useful. Irons are not allowed due to fire hazard.
Kids under 18 can 'play' but they cannot buy the cards and cannot collect the winnings so you better be the one to yell BINGO! <G>
Seafood and soups. Best soups anywhere!
Desserts are many and varied and there is always something there that you will love.
Some of the chocolete stuff is VERY rich and some foods can be very spicey but they are noted.
Bring an extention cord or power strip. Very handy. The most important thing may very well be sunscreen not only for your body but for your face as well. The sun in the Caribbean is very hot and even those of us who live in Florida can and sometimes do get burned.