...and the Scots, and the Irish both Nationalist and Loyalist, and the Cornish, there was even and independence movement for Yorkshire at one point recently...
I expected the British discussion. You apparently don´t even need a nation in order to have a "nation-state". Fellowship of another kind, a cultural one, a historic one. As I said - a natural, yet - difficult to define entity. It feels natural, and it´s enough. EU doesn´t. Particularly not if turkey os going to join.
If you think 'Britain' is a natural entity, go ask a Welshman why they have a seperate Parliament, or a Scot for that matter. Our Celtic fringes tend to want to be seperate countries. Heck, they even have different football teams in the 'World Cup' (England, Scotland, Wales, Northern Ireland) Mind you, is France a Nation State? Ask a Basque. But yes, I take your point about the EU. We are too different, and with too much bad history, to get along extremely well immediately.
You have such fringes everywhere. Even in such a monolithic countries like the Scandinavian, you have fringes, not exactly satisfied. I think that, what counts is the "core" and how large the core is vs. the fringes. The other "test" is what happens in times of danger. Britain became one united fist in WW2 (or am I wrong again?). I don´t think one could expect anything remotely similar in EU. In my opinion, a national state is a reality and a natural and necessary subject of politics.