I think this scenario has some great ideas and a nice base story line. But just remember, this is not a "Ready to Play" scenario. You'll need to take some time to think of ways to merge the details with your campaign. If the details don't fit or don't make sense to you, then change them. The base ideas in this are good and can withstand a lot of changes if required.
One big flaw, that is easy enough to fix, is the size of the cemetery. The cemetery described in the scenario is more than twice as big as the largest cemetery IN THE WORLD. But this is an easy fix. Just spread the action over more than one cemetery. Problem solved.