We likely won't agree as to the EU's importance and validity here. Most of those difficulties you perceive as being negative, I view as inevitable growing pains. Lest we forget, the EU is an ongoing project, far from completion. You'd have to allow as how any such ambitious undertaking would invite a plethora of unforeseen problems, and even dangers.
I'm pro-EU since, on the plus side, I believe that for one thing, membership of this planet's foremost and most powerful economy can be no bad thing. Even if in terms only of GDP, the EU now represents the absolute vanguard of economic excellence. Even the US is now secondary to it. And China has an economic clout around one third of it. The Euro has replaced the Dollar as the reserve global currency. This, even in light of it being incomplete, and beset with obstacles. Imagine how much more powerful it would be, were it running seamlessly. With greater wealth, we find more numerous possibilities for social development, running the entire gamut of advantages, from such as health and education, to environmental conservation and defence.
The project is a work in progress. All these setbacks will iron themselves out in due course. When they do, Europeans shall be able to boast superiority in just about every field of endeavour.
Nationalism and restrictive sovereignty are surely not the answer to Europe's woes. The entire history of the region is awash with the blood of mutual competition. The same conditions that gave rise to it's bewildering catalogue of armed conflict and persecution. You remove the national component, and these things fall away like snake scales. Since the inception of the EU, Europe has (with the exception of the Yugoslavia debacle) enjoyed it's longest period of historic peace.
For myself, the benefits (both immediately apparent and potential) of the EU far outweigh the cold comfort of hoisting aloft a flag at a rally.