The "suggested" tipping amounts add up to about $11/day per person. A 15% "auto-gratuity" is added to all drinks purchased at the bars and in the dining rooms. You can add to that at your discretion. There is a $5 surcharge if you eat dinner at Palo, the adults-only alternative restaurant. Palo also has a champagne brunch which costs $10. And, if you order room service, you should tip the person who delivers for you (if you order drinks via room service, the 15% auto-tip applies).
Other things that cost extra include the arcades, shore excursions, spa treatments, photos from the ship's photographers, wine tasting, and probably a few other things which escape me.
Soda is free in the dining rooms with meals, but costs extra from the bars and room service.