Cool! I just discovered the mouse-wheel shortcut for shuttling video when your mouse is over the transport/shuttle section (under the video/audio track names on the Track List).
Now I've reprogrammed my MS mouse so the wheel button is the [SPACE] bar in Vegas. The result? One-handed, frame accurate shuttle with play/pause!
And, even better, it works in Video Capture, too!
Hope this isn't old news to you folks, but I was so excited I had to share!