I just discovered this really great presentation: This AU 2013 presentation by Mario Guttman from CASE really helps to structure the thinking around bidirectional syncing of data between Revit and an outside database:

The collection and management of building data, including the requirements for rooms, equipment, and other needs, as it evolves from early design through construction documentation and as a basis for facility management, can be enhanced through advanced techniques in Autodesk Revit-based software. This includes linking to an external data source, automating the creation of areas and rooms, creating room data sheets, and other graphic and non-graphic processes that complement BIM. This class covers basic database theory, the structure of objects and their relation to data management, and Revit techniques for implementing this general theory in actual projects. We also discuss third-party software and customizations, and how they are used to further advance these processes. The class goes beyond learning Revit commands and looks at the underlying information requirements of emerging integration in project delivery.

Download the presentation and supporting files and find out more at this Autodesk University 2013 Live Stream site ..