4. Why is Cobb's subconscious projections following him around into other people's dreams? Why doesn't that happen with the other guys? Are they trying to say that the entire thing was Cobb's dream?
I thought there were two answers here. First, Cobb is more emotionally disturbed than the other guys, so more stuff that he has no control over creeps into his subconscious. Remember also that the security forces in the deeper dreams are all creations of Fischer's subconscious. I think the movie is constructed such that it's possible to interpret the whole thing as Dom's dream.
5. How are they actually getting into other people's dreams? Are they psychics? There doesn't seem to be any special "power" or "rules" involved in doing it, or special machinery. It seems that they are supposed to be in the same room, but that's it.
Well, they do need the dream to be constructed first (in a computer, I guess?), and the machine enables them to share the architecture of that dream. I guess you need to be hooked up to the machine with wires? Whether the wires need to be connected to your brain, or to your soul, the movie doesn't say.
6. When Cobb finally gets home to LA, how is his father, the professor, there to meet him? Wasn't he teaching in a school outside of the States?
I think it's possible to read the ending in several different ways. 1) We end the movie in the real world. 2) We end the movie in limbo. 3) The whole movie has been one massive dream within a dream, and we have never glimpsed the real world at all. (remember that the movie begins in the limbo dream world, and we work our way back there over the course of the film).
This is one of the things I loved about the movie: it doesn't make it easy for you to figure everything out, and it's really quite ambiguous. And just like a dream, the movie can be interpreted any number of ways. Personally, I think this is a remarkable achievement, and not a weakness of the film.
I know there are more questions. These are the ones that immediately come to mind.[/QUOTE]