There are so many things wrong with your post, I don't really know where to begin. First, Communism is not a form of government, but an economic system. Unlike Capitalism however, communism only tends to survive when supports by an authoritarian regime, and normally they tend to be more totalitarian than anything. This is because economics permeates everybody's day-to-day lives, and dictating how the economy works requires dictating how day-to-day lives work.
On another note, you mention that it is IMMORAL for a corporation or any foreigner to own land in another country, and yet, you blame the US for the embargo.... This does not compute. First, the whole premise of free trade essentially requires that foreigners can own land, or own "something" in another country. Otherwise, why would they trade with the other country? What would they get back in return. Currency needs to be backed by something, and normally it is based on the countries economy, and being able to buy things from the economy. By your own logic, China is an evil immoral country, not because of their human rights violation, but because the government and the people/corporations in the country own huge chunks of land in the US, as well as trillions of dollars in government debt. Do you think the US should be allowed to write off the debt, never paying it back because they don't want another country to own so much of our country? In my view, that is stealing (what a government does best), and is immoral. It would also likely result in a huge war with china.
I agree that many US policies were constructed in fear, but I don't think we're the reason cuba is a disaster. Unlike Cuba, China threw away much of their communist control over the economy, and has reaped the rewards. If China was still a highly communist country, the fact that they are pulling Avatar wouldn't surprise anyone. It would have been more surprising that Avatar was played in their theaters in the first place.
Also, your argument of: "If the Cuban people want to try communism, that's their right." implies that the Cuban people wanted the system Castro through in place. Like many communist revolutions, the Cuban people wanted changed from Batista, as he was doing some bad things. Many of them desired freedom, and a free form of government, and Castro, at the time of the revolution praised those ideals. Batista got toppled, and Castro took control with an iron fist, quickly jailing many of the same people who helped put him into power because they wished for a limited government, and the freedoms associated with that. Some of the people may have wanted what Castro wanted, but I doubt the majority of those who fought for the revolution would have if they realized that A) Castro would retain power for the next 50 years or so, and B) the ideals of freedom would quickly be dropped, etc. This is a case of people making a bad decision, acting rashly and making a bad situation much worse. Governments are quite good at doing that.