1. Renounce your german citizenship
Life is all about maximizing your options. When you renounce your citizenship, you lose a citizenship and you reduce your options. It is a drastic remedy. Without knowing his exact factual scenario, this is very bad advice.
Why? Even if the Green Party implements global taxation based on citizenship, just like the U.S., he may have other options. For example, U.S. citizens can reduce their tax rate from 40% (or even over 50%, if they live in a very high tax area such as NYC) down to 15%, or even less, by moving from the U.S. and creating an offshore business.
why holding a nationality that gives you more problems than good things?
Perhaps you want to visit your elderly parents, or other family members, whenever you wish -- and perhaps that is worth more to you than any amount of money. Perhaps you want to live elsewhere in the EU and you need an EU passport to do that. Perhaps after several years, you discover that living offshore is not for you and that you would prefer returning to your homeland and paying high taxes, rather than living elsewhere. There could be 100 reasons.
with each day,the UE turning more into a kind of soviet union I hardly doubt that so much expats would return there
Sometimes it's about existence of good alternatives. Even the USA is turning into a Soviet Union right now. Seems fashionable these days.
It is simply historical cycles repeating themselves. I listed three books on the topic in this post:
true and plenty of expats are renouncing to their citizenship
