Right. I believe Fusion organizers are quite open to getting contacted by those who want to perform there (besides music - I have no idea how the music lineup works), so in that sense it's open to everyone, but it's still all planned out in advance. They also get a few thousand people to help with build-up and tear-down in exchange for free tickets.

Last year they had some weird cyborg racing thing going on, and I also remember people performing a dance routine on top of very bendy tall poles. Last two years or more, they had a system of phones that usually connect you to the wrong place, and I met one of those involved people outside the event (twice actually). There is definitely random stuff happening, but yeah, as I said, it isn't Burning Man.