My son (age 7, an only child) just started at a small local democratic free school a few months ago and it has been SUCH a blessing! It's a tiny group of kids and we knew some of them from church already (unitarian) so we fit right in. As for not knowing what goes on at the school, my son has told me it's a "secret" but that is just HIS way of saying, Hey, Mom, I finally have something of my own here! :-) I respect that distance and I do not pry. Sometimes he will proudly tell me what he did during his day. I leave it up to him. But once, before I realized that this was important to him, I did ask the "teacher" what they did, and she happily gave me a big long email full of details for the day. So I don't think it's that they want to keep anything from us in a creepy or secretive way, but instead to regard the children as separate, whole people who don't really need us to be involved.
He is there only two days a week, 5 hours each of the two days. If the kids don't decide to do anything academic in that time, so be it....we have time outside of school for that. But it has been nothing short of a blessing for us....their democratic and respectful methods are such an education for us as parents as well as for our son. He is now feeling heard in a way that he never was before, and his little group of kids gets along well and works out any conflicts peacefully etc. There are only 6 kids ranging from my son's age up to age 14. Two staff members. But it is a new school so I expect it to grow.