The origin is that banks can lend money without any risk. End of story.
Banks get interest for various reasons - one reason is risk of not seeing the money again and that has to be a real risk or banks will just lend money without thinking twice.
By what mechanism? Each round of cuts drives up unemployment and poverty, and cutting expenses hasn't solved the deficit because trashing the economy has destroyed tax revenues.
The first few rounds were rationalization, but they were too little too late. At this point the deep restructuring that's still needed is unapproachable - it's too slow and too unpopular, and the economy is already too weak. The recent cuts haven't been sensible and structural, they've been deadline-beating short-term moves to unlock a new tranche.
Germany gains from this, certainly, but by making an example of Greece. It deters other high-debt Euro nations from getting into the same state, but it's not moving Greece closer to functionality.
No, it hasn't. The "primary surplus' doesn't include any debt repayments.
If fact, I think that, as the data show, it's in the same league of 'Trickle-down economics'.
By the way, how injecting money in the hands of a chosen handful and taking it from a country to try to pay back can make a viable and competitive economy?