US and Canadian citizens do not need a regular visa to travel to the Dominican Republic. However, you must apply for and obtain the official eTicket – the online electronic travel permit, which is mandatory for everyone wishing to visit the Dominican Republic.
Resort excursions cost 30-50% more but include transportation and insurance. Book independently through reputable tour operators (check recent Google reviews) for better prices and smaller groups. Never book with random people on the beach.
At established restaurants and resorts, yes. Avoid street food your first few days until your stomach adjusts. Ice at restaurants and resorts is made from purified water. The issue is usually raw vegetables washed in tap water at small local spots.
For a resort day, $20-40 for tips and any extras. For a day out exploring, $60-100 in a mix of USD and pesos. Don’t flash large amounts. Use your hotel safe.