Hi!
I don't know what the implementation status is for generated URIs like http://www.wikidata.org/value/8000228965cf554cf1baf641980f657d, since we cannot resolve them so easily. One way would be to redirect to a suitable DESCRIBE query result on the SPARQL endpoint. But this may require some more implementation work first. I think our main goal should be to have proper RDF replies for items and (all URI variants of) properties.
That's an interesting idea, did not think about it this way. I'll try and see if it will work.