Yes! U.S. dollars are commonly accepted in Belize, as long as they have no rips or tears on bills. The exchange rate is a constant 2:1 exchange. If something costs $4 Belize, that is only $2 U.S.
Yes! You can use a credit card almost anywhere in Belize. Typically Visa or Mastercard. Make sure your credit card company knows you will be out of the country, to avoid canceled transactions.
March is typically a warm and dry month. It is highly unlikely that you will need a rain coat or long sleeves during this time.
Yes! You cannot travel to Belize without a passport. IMPORTANT NOTE: Your passport must be valid for at least 6 months after traveling to Belize.