Hi Rod,
Regarding mapping between GUIDs, I suspect the mapping may get very complicated, and a simple tree might not be appropriate. Attached is an example of relationships between names in MOBOT, based on RDF I generate for LSIDs for MOBOT names.
I think the diagram you sent seems complex only because it endeavors to create direct linkages between name objects. As far as I'm concerned, the only linkages shown on your diagram that should be treated as a direct NameObject-NameObject links are the "basionym" links (actually, in my view, this kind of relationship does not even need to exist at all). All of the other links should be routed between and among Name Objects indirectly, via name-usage instances. The complexity is then passed to the network of name usages, and would not affect the mapping of Taxon Name GUIDs that Peter described.
Aloha, Rich