Re: HDTV problem.
Usually, most HDTV only recognize very specific resolution, like 480p (640x480x60Hz), 720p (1280x720x60Hz) or 1080p (1920x1080x60Hz).
If you can connect both at the same time (monitor + hdtv), this should be easier for you. Just debug your settings on the monitor until the HDTV works and then switch your displays. Extend your display from monitor to HDTV to start with.
As the universe is curved, there cannot be a straight answer...