Yes but it is your decision and economical profit is a fact. This is something like signing plenty of the international pacts and agreements.
Also, the EU then reserves the right to even influence your domestic policy such as gays in the military. (There are already cases on this subject) The way your country does its banking, trade, and so on.
Not true, some EU countries allow gays to serve in military and some not, Brussels has nothing to say here.
The EU is not just some club it's an economic answer to the United States. It's a race for global influence and resources.
I hope that you dont think in such categories that everything what is going on in the world is the answer to the United States and hasnt any deeper sense. Beside economic competition is healthy a lot more than military conflicts.
At least it's a bit more complicated than it was, say, about six months ago. Before that it was "do you want an EU in the French image or in the French one?"