I agree with practically everything you say except the last bit.
First, the Greek wages-to-productivity ratio must fall, by a combination of (1) Government-sector wage cuts (already started); (2) productivity increases in the government sector by (a) insisting that government workers actually do their job (b) firing redundant government workers and (c) privatization and (3) wage reduction and productivity increases in the private sector – made possible by freeing labour laws.
However, raising taxes makes the wages-to-productivity ratio worse, because it increases the cost of hiring the worker without a corresponding cost to productivity, or equivalently increases deadweight losses. Instead, wage cuts in the private sector should be achieved by freeing the labour market (which is currently among the most restricted in Europe). In fact, workers need to be compensated for the wage cuts by tax cuts.
As an aside, tax cuts would also increase compliance, which is the key problem with the Tax system (far more important than the rates).
Regarding the source of problems, clearly they all stem from the behaviour of Greece (both the country and its people) and not of the creditors. Greece cooked its books before joining the Eurozone, and the Greek voters had ample opportunity to vote for free-market, better-government and smaller-government reforms in the years since.
That said, the original creditors (eurozone banks) who lend to Greece until 2010 knew all this full well and decided to extend the credit anyway. The earned the interest rates they demanded, and should now have to eat the losses when, following the crisis and resulting economic contraction, Greece can't pay back. These banks may have had to suffer, but lending to sovereigns carries default risk (just like lending to private entities carries bankruptcy risk).
What you are ignoring, however, is that the people of Europe were not creditors before their governments decided to take on the debt in 2010 (giving the banks a 50% haircut). Since the governments of Europe voluntarily decided to make public what previously was debt to private entities, they shouldn't now be able to turn around and claim that the taxpayers of Europe will suffer unfairly if the debt isn't paid. If the taxpayers were concerned about non-payments and didn't want to go into the debt vulture hedge-fund business they could have left the bad loans with the banks who made them originally.
I personally thing that. beyond being against the EU treaties, the bailouts of Greece, Spain and Italy were also ill-conceived and morally wrong. But having gone into the sovereign loans business the EU can't complain about facing default risk.