Culebra (CPX) is out of the question. 2600 ft with a big hill right at the end of the runway on one end and the lagoon on the other. But if you do get in. The Happy Landings bar is within crawling distance of the runway. Because of the trade winds 90% of landings are over the hill. A Britten Norman Islander has a hard time with a headwind.
Vieques (VQS), Has a good runway. But the Navy likes to bomb the good beaches.
I cant think of any other islands with runways around Puerto Rico.
Man, now you got me missing sailing around the islands.