There's a vaguely fascist flavor to third world nationalist regimes that nationalize foreign assets to "take back" the country from foreign imperialists. Rhetorical differences aside, a fascist Cuban economy could look close to PRI Mexico with nationalization of foreign assets and some dirigiste and statist practices like state-owned companies, but with private property and market mechanisms largely left in place.
Cuba expended massive amounts of human and economic resources providing troops and advisers for conflicts around the world where the USSR had some interest, there were Cuban troops in places like Ethiopia and Angola. It's hard to see how that directly benefitted Cuban security or the Cuban people, they would be better off with Castro's interventions abroad.
Whether the US would do business with an ideological fascist in Havana is an interesting question. Cuba on its own isn't a threat to the US, its danger is in providing a base for for foreign powers in the US's backyard. If the US goes against them, a geopolitically Cuban government would need to rely on a combination of a native military industry and support from a foreign power to ward off US intervention. Castro could still end up making friends with Mussolini instead of Khrushchev, maybe Fidel would be nicknamed el duquito (the little duce, an italian cognate of Duke in English) by his detractors ATL.
Castro's political style of dictatorship was closer to Juan Perón or Mussolini than Stalin and Mao. As homegrown communist regimes go, it seems to be much less bloody than horror stories like Russia, China, and Cambodia. Geography plays a role here, it's easier for Cubans to flee to the US
Cuba's population could be about 10% larger without communism, most of the ~1 million people who left between '59 and the early '90s would still be in Cuba. Most of Cuba's small jewish community has been allowed to leave for Israel, but I don't see antisemitism becoming a major cause of Latin American dictators. The situation of public health would be vastly different, Cuba treats healthcare as showcase for the socialism's success like Soviet Olympic medals, and there's a similar gaming of the system and manipulation of statistics. Doctors have an incentive to under-report infant mortality and treaty health statistics like Gosplan production quotas.