Couldn't you connect with fans equally well with some kind of "likestarter" campaign where you say "we'll only make the movie if we get 100,000 likes on Facebook"? That wouldn't shift financial risk to the fans.
Financial risk!? I bet the risk is higher you incur a medical bill just thinking about how up in arms folks are about fans being able to donate direct to Braff -- the artist -- AND probably being delivered half a dozen goodies.