This could be a helpful thread for everyone who makes business.
As a swede I have sadly nothing to contribute with here. If there is Tax-haven in this world, Sweden is Tax-hell for sure.
My experience is that many countries have quite large fees in banks and others which makes it a bit costly to arrange for business in their countries even if taxes are low. To maintain a company has a bill too.
Difficult questions could also be international tax-agreements. The overall safety of the banks is also something you have to consider in a suggested Tax-haven.