Clown training is another place to look for falling skills. If you can find it -- film festivals are your best bet -- Circus Dreams
is a good documentary about circus training generally, and particularly mental aspects like handling fear. http://circusdreams.net/index.html
Systema falling skills are worth a look, too. They talk about formlessness generally, and when falling in particular. Anywhere you hold tension is a place that's vulnerable to both acute and chronic injury. Their advanced training includes stuff like getting shoved backwards down flights of stairs...