It sounds like an interesting way to do conferences and maybe a good way to alieviate the child's fear of what is the teacher going to say. I know my son has nightmares about P/T conferences. He is sure he is going to be in trouble. So far I've not had negative words with him about any conference.
However, I know that I bring up concerns that I don't want to discuss in front of DS. I like the idea of the survey. I think that would be great to have the child fill out and then have the parents and teacher discuss at the conference.