Frank, you make good points in your first paragraphs, but then you say:
"The huge trade surpluses Germany runs with the rest of the Eurozone remains the key destabilizing factor and the Growth and Stability pact needs to be amended to penalise structural surpluses as much as deficits."

We all know it needs to be.
It will not be. Not until a crisis forces the thing to collapse. Because Germany has hugely benefitted from this (Germans may not have, but they have been told that it is because of those lazy Southerners). You say that if Greece did not leave with Syriza it never will - a much stronger similar argument should be made with the pact (Greece may eventually conclude that following the diktats is clearly disastrous, while dropping out would mostly bankrupt non-Greek banks).

So if something needs to be yet won't be, then the feared outcome will happen. Not because it is particularly straightforward for it to happen, but because you can't forever cheat arithmetics.

Earth provides enough to satisfy every man's need, but not every man's greed. Gandhi