|Why do you need that image installed as opposed to a fresh installation of WinXP.|
The way Windows 7 pro & ultimate work is that you are allowed to download a special version of WinXP pro from Microsoft, complete with key to run in virtual mode in Windows 7. The idea is to run programs that can't run in Windows 7 without having to reboot.
Many times this isn't even necessary as Windows compatibility modes will allow hardware/ software to run in 7 without that bother.
Your question in #4 is confusing. If you have a ghost image of WinXP that was made using the current hardware then you install (ghost) that image to a partition on your hard drive then install Virtual PC 2004/7.