Valid points but I have some objections.
What you described is mostly descriptive while I argued purely normative. That doesn't make your arguments less true but we have to acknowledge the different viewpoints. The problem with the EU is that is not a government, stuck in some sort of limbo in-between sovereign European states and people that would like to see a fully integrated European government. I myself living in Germany would like to see such a European government if the structural issues within the EU are solved (e.g. lack of democratic legitimacy of the European Commission).
I agree with you on the currency issue. But it is solvable through more European integration and solidarity. In the US for example some states are economically weaker, while others are economically stronger. A fiscal union allocates federal taxes to the weaker ones, in order to ease economic differences. Such a model should be considered in the EU.
What worries me most about the current state of the EU is the pessimism. Yes, there are pressing issues and controversies but instead of choosing isolation (e.g. Poland and possibly the UK) we should rebuild and innovate what fundamentally is a rather successful project. Prosperity and peace are at an all time high. These all time highs are in danger now but can't be solved through reverting back to national states. Problems are global now and therefore have to be solved globally.