Piece of bollocks
The article blames the common currency for problems that have nothing to do with the currency: Economic bubbles are inflated when reckless lenders lend to reckless investors. It doesn't matter in which currency the transactions are booked. You can only argue that the reckless investors had an easier time to find reckless lenders because the latter failed to recognize that an invested Euro in a German factory might offer different returns from an invested Euro in a vacation apartment on the Spanish coast.
As to recovering from the crises, having a separate currency can be helpful because the debt can be inflated away. But history shows that inflation is rarely painless for a country or its people.
Europe needs smarter banks with better understanding of the different European regions, Europe needs a more flexible budget that puts money where it is needed (independent of national borders), Europe needs free flows of capital and people to smoothen out regional problems. Europe does not need border fences, import taxes and separate regulations for each market.
I live in Korea and just build up a lab. I now waste a lot of time and paper with international orders and customs, much more than I did in Europe. Often we end up paying 20-30% extra to get a company handling the import -- don't tell me that this is an effective way to do business.