I have a collection "Authorized Google Earth Installation". I also have an "Unauthorized Google Earth Installations" collection. The latter being based on a "Not in" query referencing the former. Is there a way to trigger an update of the "Unauthorized" collection each time the "Authorized" collection is updated?

There is no native way to do this. You could do this via the SDK but that will be alot fo work.http://www.enhansoft.com/