Eurozone is entering a time of radical change, it will be unrecognisable in 10 years, it will be a much more flexible model. In current world economic terms that might appear a weakness but in fact it's going the way of the world generally, towards a more complex system that in fact will be stronger and better.
The old ideas of regional economics are on the way out anyway. We are close to a world economy and world politics. All this nonsense fatalism and drama about Britain/Eurozone etc will look like a small local spat in world terms in years to come. All the talk of "mistakes" and disasters are lacking insight and perspective. Things are taking their own course anyway, there's nothing wrong here.
Which is not to say there won't be loads of upheaval. But don't let the scaremongers distract and deflect. Upheaval can be very good. The real problems of our world are energy, water & waste. If these aren't solved in 50 years, maybe 25, we are all flucked anway