First, Yes you WILL need a passport. Grandeur is a beautiful ship and the ports (Cozumel,Costa Maya, & Belize) are great ports that won't disappoint. I'm not sure about the soda card price & I don't recall having lobster on that short of a cruise but it could happen. As far as the cabins go, that's really up to you. I prefer a balcony myself. I would also advise you to pack a small umbrella. You never know when a short shower will happen! It has happened to us a few times & it really saved us from walking around in wet clothes. Hope this helps..