Rebecca Laffar-Smith at 2012-02-14 23:48:06:
I think this is a fantastic idea, Scott, and not crazy at all. Sometimes, we get very close to our characters and really do feel a sense of them being real.
I've recently been reading The Writer's Tale: The Final Chapter by Russell T. Davies and Benjamin Cook. In a way, what Russell does in his letters to Ben are just like your script diary. He talks about the life of his characters, and his evolving ideas. He also debriefs on the chaos of life and production as well as the highs and lows of writing.
Writing a script diary like this is a valuable tool for reflective thinking. It also gives us a chance to get out the junk without feeling like we have to put all that junk into the script. I imagine the amazing journey it would be to read back through those diary entries to see your own growth and development as a writer.
Have you ever considered sharing parts of your script diary? I imagine it could be a fascinating tool for other screenwriters because it documents your process. Having that kind of inside look in to the way it unfolds for the writer has always drawn me into the writer's world which is why I love coming across blogs where writers write as if they're keeping a journal of their thoughts as they write. It is also why I am loving Russell's book. It is a window into the world of a real working writer.