Is there an "under the hood" way to increase the video display size in the capture window of Vegas 8.0c? You can undock the capture window and drag the window to full screen size but the actual video displayed is still a relatively small percentage of the window's size.

Right-click in the window and enable "Stretch Preview to Window".

Right-click in the window and enable "Stretch Preview to Window".

Do I need to actually have a camera attached to see this choice? I don't see this when I right-click the preview window in the capture window without a camera attached. I only see 'transport', 'capture' and 'device'.

Do I need to actually have a camera attached to see this choice?

Not if you're doing SD capture which, as it turns out, you aren't.
It doesn't look like this is possible in the HD capture window.
Sorry :-(