I am from Belgium and we had the Belgian Franc. I remember very clearly how in the 90's It had huge shifts in value against the USD. It went from 27 Franc for 1 USD to 45Franc for one USD and back. Ofcourse alowing these swings to happen might have been the way to go as opposed to the Euro covering up all the imbalances for a decade because of it's one size fits all structure. One thought however is the shift in debt ownership. Belgiums debt used to be internally owned Japan style as it is more than 50% owned by foreigners today. This build up has taken place since the Euro was launched. Good or bad? Who knows.
It was weird they were individually up or down but not all down at once. So it is a comglomerate of failure now.
It's a paradox of safety. First it provides more protection then the structure provides more risk. Personally I don't think that should be a reason to keep everything as isolated as possible rather I would hope the period of safety should be used for the good. But obviously that is easier said then done.
Read my book. Free download. It explains all of this. Plus solutions towards the end. http://morganisteconomics.blogspot.com/p/publications.html