I am very interested in some of those questions as well.
My understanding is that since the revolution, there have been three types of Cuban immigrants/exiles in the United States which have a basic general chronology:
The first part are those who were part of the pre-revolutionary power structure and hopped on their yachts towards Maimi in the very beginning of the revolution;
the second group are those who, though originally were in favor of the revolution, became disillusioned over time;
and the third group are those who have come purely for economic reasons just as we see immigrants coming from nations all over the world because they can make some more money. The only difference is that because they are Cuban, as long as they can get set foot on our soil, they cannot be deported (Getting picked up by our coast guard in the ocean doesn't count - those people get sent back).
Unfortunately, because the first group was the first to come to the United States and they had a fair amount of wealth and influence, they were the ones to set up the Cuban-American/Cuban Exile power structures (Cuban American National Foundation CANF) which are arguably as repressive as the current cuban government. These are the people who claim to be the Cuban Government in Exhile.
Frankly, its doubtful as to whether they would be much better than Castro. I don't think the Cuban people would be very happy about it either. It would be kinda like returning Russia to the Tsars after the Soviet Union collapsed....