Subject: uri-representation of hierarchical resources in decision requests
just a quick thought:
A part of your proposal deals with the issue how to represent hierarchical resources in a decision request.
It seems to me that your motivation is to have a kind of normal-form to represent different sorts of hier. Resources. Why not transforming them into an xml encoding and using xml as normal-form?
XACML is xml based so this is maybe a more natural representation than through xacml attributes.
Further the xml case offers very powerful mechanisms.
Could this be an approach for your use case too?