If these guy's have 1,000BTC to put up for insurance then they can also buy their own offshore fully legal brokerage/securities trading financial services company and do this on clearnet. Nothing illegal about anonymous directors running a brokerage service in Belize, Panama, Seychelles, or even New Zealand if you have a local employee there. As long as you are licensed in that country you can operate. Hell you could operate a legal brokerage out of Liberia.
I'm interested, but can you respond have you considered that^^, and why you are not implenting this that^^ way?
In other thoughts, I'm pretty sure that this is going to be one of the main reasons when the feds start their attack on bitcoin.