Winning independence only to lose sovereignty?

If Angela Merkel's comments on European integration were not frightening enough, we now have the president of the German Bundesbank, Jens Weidmann, saying that "In the event of a country not abiding by the budgetary rules, national sovereignty would be automatically transferred to the European level on a scale that can ensure compliance with the objectives." What exactly he means by the 'European level' is unclear, however what is totally clear is that, in return for Germany propping them up financially, Eurozone countries will have to toe the German line with regard to their spending or else face losing their financial sovereignty. Now, given that the SNP want Scotland to be an independent nation in order to have control (ie sovereignty) over her own financial affairs, does it make sense to consider even for one moment becoming part of the Eurozone? Of course it doesn't. Unless, of course, the SNP have got so used to being able to blame someone else for not allowing them all the fiscal levers they need to manage Scotland's economy that they can't cope with the responsibility which sovereignty would bring.