Well the problem I see is as per that video is that wealth is too heavily distributed with the top 10%, hell even the top 1%, if the wealth was a bit more evenly distributed it would still get spent but there would be less poverty and a definite improvement of living quality for pretty much everybody. Plus the money doesn't disappear just because it's taxed, it's just moved to the government which can invest it somewhere as well.
A problem is that once money reaches the Cayman Islands or wherever it essentially becomes invisible and the persons or corporations can swindle them off to do whatever.
So in my opinion the movement of money towards these places should be hampered and double taxation legislation should be lightened so that if country X has 5% tax and country Y has 50%(yes this figure is intentionally exaggerated) tax then even even if a corporation moves it cash from country Y to country X country Y can still take the differing 45% in tax, this would obviously be a problem for tax paradises as it'd destroy their "business model". At the moment where such double taxation laws exists it simply prevents double taxation and the tax where you register it is what goes.
But most blatantly we need to prevent corporations and the top 1% from buying politicians, regardless whether they do it legally or illegally.