Very good explanation of the situation. What they forgot to say is that the Union promoted and offered these loans. They calculated how much each country can and should borrow to boost the economy and divided this into certain areas. The countries allowed their citizens working in that areas to apply for loans, financed with these money borrowed from the union, which caused an enormous amount of frauds.
For example someone forced a bill in the EU saying that there's not enough forests, so now you could get a country to pay you (with the money borrowed from the EU) if you planted some trees on your land!
I also don't think the countries will allow the fiscal union to exist, this would mean that a government far far away can reduce my pay or make me fired and to protest I'll have to travel 3000 km
