For October through November, we recommend 4-6 months in advance. Over 100 restaurants are located in about an 80 square block area offering about 15 different cuisines ranging from real Mexican to Thai. A lot of restaurants offer sidewalk dining along Playa's famed pedestrian-only area known as Fifth Avenue. No, because of high mineral content. Most homes and condos provide bottled, purified water as part of the rental.
Restaurants prepare both food and ice with purified water.
More than you could ever do in one lifetime, from watersports to ecology parks to Mayan ruins to shopping to colonial cities. Don't worry about it. Most natives in the travel industry speak English and other languages. If you get to an area where people do not speak English, well that's just part of the fun. The locals are friendly and helpful.