Agree with all you said, should have indicate clearer my response was on the first line of your post in isolation.
The problem for Greece will be that their debt is mainly in Euro, not in their new currency.
Leaving the EU will be another problem for Greece. In 2013, they received 7.2 billion Euro from the EU (http://ec.europa.eu/budget/mycountry/EL/index_en.cfm) of which 59% went to 'Regional Policy' which is described as:
The largest share of the money that Greece received from the EU budget in 2013 went to its regions (59 %). EU regional policy aims to reduce the economic, social and territorial disparities between Europe’s regions and countries. Regional funds invest in projects supporting job creation, competitiveness, economic growth, improved quality of life and sustainable development. Transport infrastructure and the environment are top priorities for Greece.
(Note, Greece pays into the EU as well, so the balance is not 7.2 billion but nonetheless it will affect quite some ongoing projects funded by the EU)