Thank you Peter, i really enjoyed reading this piece. Your down to earth, pragmatic approach to the discourse is refreshing and it does much to support the profession of dance movement psychotherapy throughout the world. There are professional associations in almost every country now and Masters degree training in many of those. Please see my new book 'Essentials in dance movement psychotherapy: international perspectives' which has just been published by Routledge for a full overview.
In terms of evidence, I would agree randomised trials are essential. However, there are some already. In mental health settings dance movement psychotherapy is offered alongside the others creative arts therapies (art, music and drama). Also in schools, colleges and care homes, in the community and in special education. More and more people are understanding the emotional and physical health benefits of employing creative movement and dance in therapeutic contexts nowadays.