I'm confused about Capitalism?

No, I don't think capitalism will work in reality because people undoubtedly try to find ways to cheat and screw other people in order to create their own wealth. Just take a look at the banking crisis and what happened in the case of Enron or look at the housing crash. Their main goal was to make as much money as possible regardless of who they had to run over to get there.

Don't know what video you're talking about, but Capitalism really by definition transcends individuals. Sounds like you are talking about some kind of ideal, libertarian rugged individualism.

Capitalism is very much "social" in it's own way. The "Capital" in capitalism refers to the accumulated savings of many people, being gathered up and channeled to enterprises that can invest the capital productively. As such it implies the use of banks and capital markets where many people cooperate in sharing ownership and trading.

People confuse capitalism with free market economics or free enterprise. They tend to go together but are not the same thing.

This is quite the loaded question. It depends on what you mean by 'work'. It works very well for the top level of society. The problem is there are people that were born in less privileged situations, that maybe didn't get a good education, that do work very very hard and don't make enough for themselves and their families. The idea that everyone can get what they need by working hard enough simply isn't reality. Although often that is the case, it isn't always. There has to be bottom level to support the top level in a Capitalist system.

Loaded question, pure capitalism is inefficient because of free will (a/k/a the absence of laws). Civilized society, to some point, has to have law and order and some degree of social welfare to be at the most efficient level. This 'level' is the main disagreement of the two main political parties in the U.S. and has been the cause of war in other parts of the world.

Pure capitalism is impossible. We can only get as close as we can to it. It's the same with pure socialism.