Wife and I visited PR over Christmas week a couple of years ago and our time there was enjoyable and safe. We spent our time around the western ocean front city of Hatillo which is a good place to jump off to the big radio telescope at Arecibo and some other attractions.
Virtually no one spoke English, and menus, directions, etc were entirely in Spanish. If PR wants to attract retirement age couples, they’ll have to become more accommodating to gringos.
On the flip side, there are two areas in Puerto Rico that are nearly English-only, at least as far as restaurants and hotels go: Vieques and Rincon.
We and another couple spent a week in Vieques, and all the people who tried to sell us drugs knew how to speak English.
Other than that is was great, and since it is technically part of the US we did not have to go through customs. I mailed myself many plant specimens that are now growing nicely in my back yard.
The ex-military base has beautiful beaches.