ELGG's Atomic Modeling

The 1.7 docs seemed sparse, so I am hoping the community can help me with some architecture questions I have.  Basically, my organization wants to use ELGG to provide the social requirements of a site - but the site will not fully reside within ELGG.  Because of ELGG's atomic modeling I was curious how other people are modeling their data who are using this approach.  One example is:

Let's say as an organization we don't want to use ELGG's video capabilities.  So we want to store/serve/etc videos outside of the scope of ELGG, but we want to use one user repository (ELGG's) to allow people to do things with the video.

A data mapper comes to mind, but like I said - I wanted to touch base with the community & get some thoughts.

Thanks in advance.