Compare for example today Cuba and the Dominican Republic, to get some sense of this. The Cubans have a heroic history of struggle against Spain, which was betrayed by the Platt Amendment; new generations of Cubans (everyone, really) have to relearn old lessons, sensibilities, sources of pride, etc.
As to your other queries, read Weber on charisma and its importance politically, in practically all situations; also there's no way in the case of Cuba that any kind of economic reductionism (including the reduction of per capita income et al.) can be used to explain much of anything. Castro went up against the Russinas any number of times, taking risks that the sugar deal might be dropped by the USSR.
Finally, in the early 1960s, there was much talk in the Caribbean about how to develop small countries and all that. An idea was floated, the Caribbean Socialist Commonwealth. Trade sugar, and the many sugar by-products, meat and leather, nickle and other items to Venezuela for oil -- as a barter deal to escape the trap of the law of value on a world scale. Che, with whom I discussed this in detail, when he was industry Ministry head, was trying to steer Cuba into more barter deals, and away from the world mkt and world mkt prices. Now in a small way, with the barter deal with Venezuela, a little of this has begun to come true. Of course the US will try everything to stop things from going further.
There are many in Cuba, maybe a majority, who complain about Fidel's rhetoric, his speeches, and the rest. Who have little good to say about the party rule, which runs the state, which stifles civil society. Who aren't getting enough consumer goods. Yet these same people are probably the politically best educated people in the world; they may hate shortages, and the rest. But they also feel that anyone who fucks with Cuba as an independent nation, is asking for trouble. In other words, it's less about socialism than nationalism, in my view. Nationalism in the best sense of the word. Don't forget that US cold war and post-cold war policy was and is to oppose any state that seeks an independent foreign policy, that opposes, however peacefully, US ideologic hegemony and political power. Cuba is today at the top of the list. However, because of what I've said above, there will be no invasions of Cuba by the US: the losses would be much too great. Some day a (possibly great) American president will tell Cuba, "we totally and in every way respect your national sovereignty; we are equals; we in no way see you as inferior." Once said, an excellent discussion between the US and Cuba could and would open up about Cuban socialism. This president would find much give and take in Cuba's bargaining positions, once the US sincerely and very publically respects the nation's sovereignty.