YES!!! Bring your own sunscreen of at least 30 SPF. It is pricey to buy sunscreen in Aruba. The sun is strong in Aruba and you will need to apply sunscreen regularly to avoid getting sunburned.
YES!!! An up-to-date Passport is needed for Aruba! If you have Global Entry they take that when returning to the US which is great! When returning to the US, it is also recommended to give at least 2.5 hours at the airport.
YES!!! No need to exchange currency. They also take most credit cards which makes it easy as well!
Cabs are great here! Please bring plenty of cash for the cabs as well. Some may take credit card but not all. Airport to Hotel is about $35 each way. Many places/restaurants are walkable in Palm Beach.
Yes, but chances are you won't need it! If it rains it won't last long.
One of the amazing things about Aruba is it doesn't get chilly at night! Low will probably be around 77 deg. A light sweater or two is recommended for indoor restaurants if you get cool easily in the AC.