I am curious about the regularly changing elist. Any time you make changes to the elist, you run the risk of losing data. Are you trying to preserve any data in the Contributor application between changes? Is that being done in Planning or somewhere else? I would think you would at least need to publish out the current data in Contributor so that you can bring it back into the application after making the elist changes. This would likely require some sort of ETL or mapping to marry the old elist hierarchy with the new hierarchy.
Jeff