I am Flo,
developer at Non-Lethal Applications ( the creators of Video Slave ).
First of all, thanks to Brian for his post here!!
I can confirm that he is not being paid for doing this

I would like to answer some questions here.
First of all scrubbing video :
Video Slave allows scrubbing by receiving MIDI Machine Control commands you can send from any DAW.( I think Brian is also using MMC with Video Slave so he might be able to tell you where to set the right checkbox to have DP output MMC ).
Next : importing audio and streamers and punches
I have not seen the necessity to import audio to a QuickTime yet.
But I do consider ( and Brian can confirm that ) all feature requests that come from potential users. I don't do this to sell more licenses but rather more to make Video Slave a complete toolkit many people want to work with. The version as it is now is just the beginning.
Brian asked me to include a balance pot and a volume slider and guess what's in the next update ( which will by the way be available very soon )?

What would you use that feature for? Importing a cue rendered out of the DAW into an existing QT?
Streamers and punches support is also being worked on already.
It will take some more weeks to integrate it completely though.
Hope that answered your questions.
Of course having the movie files within your DAW is ok, but in my opinion having a dedicated VTR has a lot of advantages. The most obvious is taking the load off of your main DAW machine. I have some 1080p files with a DNxHD codec lying around here that eat up almost 60% of CPU on my 2010 MacBook Pro. Organizing your movies in playlists and not having to re-encode video files anymore are also very convenient and time saving.
If you have any questions, please feel free to ask!
Feature requests are also always welcome!
Best regards,
Flo,
Non-Lethal Applications