It'll be a fairly nice place.
Not necessarily.
It could turn out just like IOTL Cuba, It could turn out like Cambodia.
Before 1789, Robespierre was the nicest guy in the world, and Castro might have been real nice before 1952-1957 as well, that's not a guarantee that power won't drive them crazy.
Pais was strongly pro-Democracy and pro-Religion before his death, but lest we forget that Robespierre was opposed the Death Penalty before the French Revolution.
Well, nevertheless, let's assume that Pais remains a, let's call him Christian-Democrat to save time, which means that he can't ally with the Godless, Authoritarian Dictatorship of the USSR, and he's a young reformist revolutionary, so that can't endear him to the Eisenhower crowd in Washington.
There might be a coup in the early 1960s, depending on how competent the ITTL CIA is.