If this is what it takes to put on a show, I can understand why performers, directors, and producers all have to be a little crazy. If they aren't nuts to start out, then doing this kind of thing will make them that way. So much has to come together and be brilliant, but it's like herding cats.
The documentary itself was saved by the decision to shoot everything. I don't think they knew what they wanted when they began the project. They didn't have a clear vision, so the narrative meanders. However, the post production saved the day to a degree. I'm sure there are hundreds of hours of unused footage for a reason, but that's just the way of things. Finding gold in all the rock is a hard job.
What we are left with is an impression of what the crucible of the creative experience is like. Nothing specific here, no clear ideas, just a jumble of creative fury mixed with ego and business. And maybe that is about as close to the reality as it gets.