We cruise carnival they have a safe your credit card controls the opening and close of it. Your laptop won't fit it in the safe should be fine in the room. My hubby just used the laptop to download digit pictures so the camera would never fill up and we could see the pictures that same day. Soda Cards I'm not sure about but it does depend on the length of the cruise the longer the cruise the more pricey the card. You can bring a certain amount of soda on board and buy sodas at the ports to bring on board. I suggest that but I'm cheap.
All the rooms I have been on any cruiseship including inside, balcony standard, balcony suite(lucky upgrade), and oceanview have been a queen sized bed. I love the new carnival bedding it's really nice. I hope that helps.