@darius probably I haven't thought this through, but why would a server require the full object to be deleted if the authoritative instance(the one that generated it) is requesting its deletion? What is the server to do if the representation you're sending is slightly different than the one it already has? Besides the ID no other information in that object is relevant.

Outside of Create/Update I don't see reasons why an Object property should be anything else than an IRI or a list of IRIs.