Is there a simple way to remove caches from the downloaded database? I have noticed that once a cache is downloaded, subsequent detail downloads do not seem to update the data. An example would be a cache that was downloaded, then was archived on geocaching.com. Later detail downloads do not change the status from 'normal' to 'archived'. Thanks again for a great program!

You can always click on "Download Details" in the geocache details view. That will ensure you have the latest data.
However, the archive/not archived status should be updated by a Download Overview.