First of all, if you haven't seen this movie and want to you should stop reading in order to not learn all the secrets of what this movie is about. Second of all, this movie is so not worth it that if you do continue to read, you'll probably know more about what happened in the movie and its secrets than anyone who's actually viewed the movie.
I've gotten a lot of hits on this site for people are looking to "What the crap went on in this movie!?" This might be a common segment if I keep getting hits like this.
If anyone has any other questions regarding what happened in this movie that I don't answer feel free to contact me at firstname.lastname@example.org. I also want to say that since I had no hand in this movie other than viewing it, the views I express could be wrong. Telling you this movie is a waste of talent is, however, correct in every way.
1) Were Zach and Avi real?
A. No they were not. Zach and Avi represented people Jake created in order to deal with Mr. Gold. Try to think of them as a split "Tyler Durdan". They were never Jake's cell mates, they never taught him about chess or cons, and that how they knew where Jake had hid all his money.
2) Who was Mr. Gold?
A. Mr. Gold was the ego Jake created in jail. Mr. Gold represents the side of Jake that wants to destroy Macha and obtain vast riches. Anything revolving around Mr. Gold's character, such as his drugs and his assistants were paid for by Jake unknowingly.
3) What was the rare blood condition Jake had and how was he saved from it?
A. It seems that Zach and Avi could have some control over Jake's body. I doubt the blood condition was real but maybe appeared to be real to convince Jake when he went to the doctors.
4) Why the animation?
A. This was to give you hints that what Jake was seeing were not only not real but also what elements of Jake's subconsciousness they were.
5) What was Zach and Avi's plan?
A. Since they were part of Jake's subconscious, he created them to help him get rid of Mr. Gold. Since Mr. Gold would use Jake to destroy himself, Zach and Avi were created to help Jake get rid of Mr. Gold. They were also trying to show Jake how to get rid of his Mr. Gold by telling him what he's doing is helping to take down Macha. This set up the "chess pieces", if you will, on how to position Jake into getting rid of Mr. Gold. Remember, Avi was the persona that taught him chess and he's the one who keeps on convincing Jake to go along with their plans. Likewise, Zach is the one in charge of setting up Macha, since he was the con artist persona.
6) Why is the movie called "Revolver"?
A. First of all I think it's because Guy Richie wanted us to believe it was an action movie. So he lied a bit. It's called that because of Jake being the center and he must deal with everything that "revolves" around him. This is more the BS explanation, but I think my first answer is the real correct answer.
7) Was Macha devolving his own Mr. Gold?
A. In a way, he already had a Mr. Gold. In fact, we all do. The main difference between Jake and everyone else is that his was a more defined separate identity.
Any other questions I receive I will put into this list so check back for updates if there are any new questions. I will just put them in the same list. Hope this helps, other than telling you not to watch the movie, this is at least some help