Around Germany and Greece there were other countries. They went by names like frugal four and PIIGS. They forced "austerity" and stricter working hours onto indebted countries to save their own banks.
The colours on this map show well that northern "productivity" is not about working hours, but about other topics that did not get addressed. Among these topics are also tax heavens (think the Netherlands) and money laundering (think Austria's special relationship with Russia).
So it was nothing more than poor political leadership without vision.
I'm confused by your statements, but am looking at moving to Germany. Do you mean if my wife works full-time and I work full-time we'd end up being paid 50% each?
No but part time jobs are paid less, so if you work full time and get €2000,- and then switch to half time you will typically get less than €1000,-.
Exactly. Plus, you usually have less career perspective if you work 50%.