(1) I think it is likely that Greece will exit the Eurozone but I do not think it is in the best interests of the Greek people
(2) I think the following article is worth reading - http://www.economist.com/node/21547750
(3) The issue for Greece is that it has no significant natural resources it can export (ignoring tourism for a second) and no strong adjacent economies it can trade with
(4) I also suggest reading Reinhart and Rogoff table 6.6 which mentions that under the author's definition of default (which IIRC includes a 20% deval) Greece has been in default or restructuring 50.6% of the time since 1800 to 2006 (actually I think Greek independence was around 1832 so that may be the start date).
(5) The key question to ask is why it requires a technocratic PM to force through change rather than elected politicians. There is a failure of democracy in Greece - but the failure is not now but over the last 20 years.
(6) Exiting the Eurozone would mean that the cronyism has no pressure to change. The nation will then continue to repeatedly default or devalue for generations.
(7) One has to ask if a Greece which has switched to drachma could stay within the EU as it is likely a switch will require restrictions on the movement of capital and people (hence breaking two of the EU's sacred principles)
(8) In that situation (ie a Greece outside the EU) why would any foreign investor choose to invest in Greece as opposed to Spain, Portugal, Italy or Ireland (if they all remain within the EU)?
(9) One has to remember that before joining the EU Greece was one of the poorest countries in Europe. Why?
(10) I think the expectations for growth in Greece under the austerity measures are probably underestimated. I say this as I believe that the public sector, by over generous salaries etc, has diverted intellect and labour away from the private sector. In addition the deadening hand of bureaucracy and graft has probably excessively suppressed the private sector in Greece. The general assumption seems to be that 1 Euro removed from the public sector is one Euro less to the economy. I disagree - if it means that the private sector retains that Euro then the multiplier is likely to be higher than in the public sector (Maudlin in 'The Endgame' suggests it might be as high as 3x for the US - I think arguably in Greece it might be even higher).
A reduction in the public sector in Greece, accompanied by a reduction in regulation, bureaucracy and both the opportunity for graft and the number of hands seeking the same is likely to speed growth of the private sector. However this will only happen under a strong PM within the EZ.