I can answer some of the questions. The Standard Balcony Cabin is 185 sf. with a 35 sf. balcony. They are of good size in my opinion. The noise is always subjective to cabin location and other factors. Empress Deck would be a good pick as you would have decks of cabins on top and bottom instead of say the Galley or Dance Club. Yes, you can smoke in all cabins on all Carnival ships *except Spa Cabins.
The Dress Attire described is perfectly acceptable on Cruise Elegant nights. It has became more relaxed in recent years. Sorry can't help with the extra lobster tail in the Steakhouse question. I would like to know the answer to that myself.:)