It's a GREAT idea - but very, very hard to execute.
Perhaps you could reach a much broader audience if you could make a movie, not about Ray Franz per se, but about the rejection of religious bigotry.
If you could then pick up a couple of other case-studies, dealing with the catholic church and another from the protestant field, then combining it with Ray Franz's history, THEN you would reach a much much vaster audience.
Here's an example on the catholic field: http://en.wikipedia.org/wiki/Hyacinthe_Loyson
Eden