On Aruba
The people are wonderful - not just the ones in the hospitality industry
The restaurants are excellent
The weather is fairly predictable
USD accepted virtually everywhere
You can go anywhere on the island safely
Therefore the AI option is not chosen by very many Aruba regulars - except for those of us who like to drink quite a bit.
Once you get away from the hotel area it is not a lush island. It is a desert and fairly flat.
Public transport between town and your hotel is cheap.
There are no clothing optional beaches - although you may see some ladies going topless on Manchebo Beach
In May it's usually dry and there are no problems with mosquitoes
You won't be comfortable wearing swiming attire down town. But there is no need for jacket or tie in any restaurant. The most you'll need are long pants and a shirt with a collar and even then only a few places have dress codes.
Have a great vacation!