If I take the uncompressed HDV analog component output from the FX1/Z1 direct to HDD (and I know I need fast processing here) can use this in Vegas? Would there be any advantage if I could? And could cineform convert the uncompressed video to the CineForm intermediary?
You can indeed use the 4:2:2 out of the cam into a component card such as the BMD card, and then if you wanted to save some space, use the CineForm codec but in doing so, you're sacrificing quality, however minimal. Additionally, you won't have ability to print the media back over the BMD card without yet another conversion.
One thing I wish we had more access to in Vegas is more codecs that the BMD card could read properly. (Direct Show would be sweet indeed)