How 'documentary' is this movie?

Beyond the actual "party" invitees, I am wondering if anyone knows how much of this movie, especially of those characters who have names other than their own real names (i.e. Jaglom, Marcovicci and Kellerman), was true. For example, were Jaglom and Marcovicci in a real life casual relationship with each other at the time? Was Kellerman actually propositioned by the guy from film crew (I think his name was Richard), or was that a set-up? Was Kellerman actually just out of a relationship as her character stated?

I saw an interview that Jaglom did with Ben Mankiewicz on TCM about the movie, Jaglom who mentioned that the people in the theater truly did not know what they were being invited to participate in, and that Kathryn Harrold really did walk out because she felt uncomfortable with what was happening.