No, tax and gratuity are not included. For most of the buffet meals, a soft drink is included for most other meals, family style or sit down, drinks are additional.
Unless it states includes NA beverage then it likely doesn't. Also note that some of the menu prices may not reflect actual, since they prices were accurate ONLY at the time the menu was received and a few are over a year old. In any case I would add an extra 10% to everything just to be on the safe side.