Good points, Gonners. I think also one of the points about tax havens, is that individuals and companies who use them a lot are in effect leaving the country. I mean this country. They have decided not to follow the rules here. Well, OK, if you want to live abroad and work there, and pay taxes. But what if you are still a UK resident? They are opting out of society.
So you could end up with a super-rich who opt out, but still want to keep political power. This seems weird to me.