I'm sure it's been mentioned several times now, but a solution such as Open Transactions could work well to maintain asset tracking, whilst simultaneously avoiding the "long arm of the law" problems. However, even that I don't think is sufficient.
There needs to be a market forming around an agreeable mediation procedure/technique/ruleset wherein we can arbitrate our disputes in an acceptable manner to the parties involved (it must be considered in the beginning of any engagement and it must be binding, IMO). However even then, I don't believe it will ever be completely solved using crypto-like transactions. Contracts always have a way to be misinterpreted, and participants in markets such as ours will almost invariable have a few bad apples.
You've stated several of the elements of the solution I'm thinking about.
I don't think that a solution which tries to achieve perfection in making a wrong'd party whole will be very tenable. I do, however, see a great value in making it likely that a scammer will lose, and that is a much easier problem to solve. Simply removing much of the potential to make money from scamming would go a long ways toward cleaning things up and making it a safer place for normal users to participate in. I would dearly love to be able to buy things with Bitcoin with something vaguely approaching the assurance I have with e-bay/pay-pal.
I just registered 'daprae.[org|com]' to incentivize myself to put some effort into documenting and perhaps coding some proof of concept stuff now that the weather in my locale is getting shitty. Stands for: 'Distributed Anonymous Peer Rating, Adjudication, and Escrow.'