Hey,
It looks like you have some pretty neat little modeling projects going on. I especially like the social domain you have, because it ties into why I'm writing this post in the first place. :)
Obviously, you seem to have an interest in RDF, so I would highly recommend that you take a look at Jamie Taylor's web_ontology type (http://www.freebase.com/view/user/jamie/web_ontology/ontology). There will probably be some schema changes soon (including a type with the freebase equivalence) and hopefully the schema will be made to reflect RDFS more closely. Basically the idea is to model the relationship between an RDF schema and (a) freebase schema(s). This combined with some tooling, will make it possible to both import and export RDF, and since RDFS is RDF itself, make it possible to easily add new schemas (with someone coming in and filling in the freebase equivalence entries for it).
