..except for: Counter party risk    Seriously though, the actual "counter party risk" of Bitcoin or any other chain for that matter dropping vital features like OP_RETURN puts Counterparty's success and longevity into jeopardy. I would go for at least one fall back in case the primary chain becomes defunct or takes a negative approach towards Counterparty's needs. Why not create a second chain faithful to Counterparty's requirements? Or a third and fourth one for different purposes? If the uses the secondary chains are meant for become successful, the chains will be supported by hashpower and decentralization. If not, they become obsolete and should be allowed to die or shrink until utility returns to them.