Freimarkets: a proposal for user assets, distributed exchange, and off-chain txns

Off-and-on for the past couple years, Jorge Timón and I have been developing an extension of the Bitcoin and (pre-OpenCoin) Ripple distributed protocols which enable user-specified bearer instruments, distributed peer-to-peer exchange, off-chain accounting, auctions, derivatives and transitive transactions, and the multitude of financial contracts having such primitives would make possible. The specification is now reasonably complete enough that we would like to receive input from the community. The PDF is available for viewing here:

http://freico.in/docs/freimarkets-v0.0.1.pdf

We're looking for public comments about this or related approaches. In particular we've spent a fair chunk of time working out how to handle coordination of private accounting servers with the public chain and derivatives contracts, both of which are basically cryptographic protocols expressed as bitcoin scripts. Input from any of the resident cryptographers would be very appreciated.

Happy hacking, Mark Friedenbach