It may turns out that doing Bitcoin exchange business in the legal form of an offshore company is very convenient, good idea! These kind of legal vehicle are used frequently in the PE investment in emergency market/stock market/tax saving situations.

 If an Bitcoin exchange doing business in an onshore company, the value-add tax, the import and export tax maybe implied, and other regulations will be tough, too, like banking\security\KYC.

But whatever the legal form the exchange is, a totally open attitude with the WHO YOU ARE information and how you work everything out,  is absolutely needed. And everybody should make deep DD into them.