This is a possible solution that others have hinted at. If there could be a way to allow for a table to be duplicated to another database and that when changes to the source database are made that are also made in batch or on the fly to all the duplicate databases tables that would make a bunch of things possible.
Plus if you could select the fields that you want copied/duplicated that would even be better.
Because then the source table can be protected in the source database. The duplicate table data would be a special read only for all in the new database. This can then be used to lookup information, updated records, link tables without the many problems. If the source is removed or changed in a way that make the link stop the duplicate could remain static but report an error. Changes would not be allowed the other way.
You could do this by batch loading the table over and over but I think that would mess up the links.
If anyone know of way of doing this now please let me know.