Roughly 45 minutes depending on traffic Tip: Grab some drinks from the convenience store at the airport! Skip the super pricey bar drinks. Sometimes the bus actually stocks beer for sale!
Personally I would say bring Pesos. This way the locals don’t need to worry about exchanging it when you tip etc Small USDs ($1) are great for tipping though. Credit cards are widely accepted as well for shopping and excursions
Yes there is! And each time I have been to Ocean Riviera Paradise, there was good connection across the resort
Do not drink the tap water! But water and ice provided across the resort at bars and restaurants are totally safe.