We were in Curacao in May. We rented from Alamo. It was $244 for the week all in. We used Amex and we have the extended Amex rental car insurance. We did not purchase any rental insurance beyond that. They were as nice as can be. You pick up and drop off at the airport. We had an early flight, so they told us to leave the keys locked in the car, which we did. There was a guard on the lot, and there were no issues.

Driving in Curacao was not a problem. Much easier and better roads than St. Martin and you certainly need a car when you are there. We used Google maps to get around. You need it; there's no road signs. It mostly worked okay except it didn't know about a roundabout that had been added in Willemstad and always wanted to route us the long way to the grocery store. It also led us down a dead-end road one time, but we figured that one out.

Be sure you do the edcard before you leave. It saves a lot of time at the airport. https://edcardcuracao.com/