"Does anyone know of work on the legal barriers to running alt(e.g zero)coin to bitcoin exchanges or acting as a third party guarantor?" Ian Miers (twitter @secparam)
Ian wrote the original paper on ZeroCoin and presented it. Pretty sure the team @InvictusInnovations has been confronted or is confronting problems in a similar domain with Keyhotee. I would like to use this opportunity to help him make a connection to some of the brightest minds in the field right now...here at BitSharesTalk.org and will send him a link when it is answered sufficiently.
I have also asked him to check out ProtoShares as a platform for his technology, so if any Devs have Twitter, Please hit him up!