In your system who is the trusted party that holds the fiat?
The issuer would be the trusted party to hold fiat. But by integrating the concept of multi-sig tx multiple issuers can issue a single Fiat and a consortium of issuer can be trusted party to hold fiat. However I will have to rework on certain elements of the paper to introduce multi-sig based issue.
Thanx for initiating a new thought line that can be added on to table.
You have looked at counterparty.io, right? Adam Krellenstein has done a pretty good job with it and it's ready to use right now.