Personal preference. Try them both and see what you like better. Having it checked may cause problems with interlaced footage. I myself don’t like it and always uncheck it.
This is really something. Any Quicktime app cannot render RGB at anything other than 8-bit.
Maybe you’ll have to use Windows. Is there a way to re-wrap your Sheer Quicktime files into Sheer AVI files without any re-encoding? I know there used to be tools that could do this for DV codecs.
Down the page, it includes a tool to re-wrap MOV to AVI. There’s a strong chance this could work with the Sheer codec as well. Then you could use CS3 on Windows (AE or Premiere), or you could convert it to Cineform and then wrap it back to MOV and get 4:4:4 in Final Cut.
I recently rented David Lynch’s “Eraserhead” on DVD. Upon playing the movie, there was a little calibration lecture. It said “You will see a shadowy image of a man. Turn your contrast to 50% and adjust your brightness until you can just barely see him”. I’m not a colorist, but I thought I’d throw that out there. Maybe a little warning on the DVD to adjust the brightness beforehand.