romania isn't using the money yet...but the plan was always to include them eventually, they are not opting out, and no one told them to opt out. but that isn't exactly the point. they are in the union and the range of difference is pretty drastic regardless.
it doesn't matter if some of the population speak english, over all the differences over that large area are just not conducive to having any national discussion, whats the point if you have to hope someone is talking in english or hope it gets tranlsated by some 3rd party into english, your experience is thus limited to whatever is officially noticed or whatever. switzerland isn't much of an example of anything they are a tiny country, they can't be all that separate within that country, anyways belgium is the opposite example, its tiny and barely holding together, two different peoples, two languages, and they pretty much want a divorce.
its not about the corporations and the rest, what defines a people still matters, just as it matters what defines your family and that defines how you will treat them. its not about the sake of independence but understanding why things work and why things don't work, the eu is a concept from the past when the blank slate was in vogue, human nature was entirely denied, the soviets thought they could create a perfect citizen, the feminists and the hippies had their communes and rejection of gender norms and the rest, this all fell apart as they denied what made people people, and in the case of the soviets, it required brutal force to keep their broken theory of humanity in place. the eu was no different, it was a denial of what culture and language are to people, and nationhood. they thought they could retrain people to ignore all that, but its clear it just doesn't work that way. what you propose is to continue this broken theory of how people are by forcing them even further into the binds of a broken system that will take away even more autonomy, it will just make the trap permanent...or until it really falls apart in a bad way down the line. you can try to force people together that shouldn't be, yugoslavia is a lesson in how it can go very badly wrong in the end.
its not about fuzzy feelings and flags. this is how people work. in the 60s they thought they could take children with ambiguous genitilia, chop it off, convert them to girls by default, raise them as girls, and have them become girls by nurture, and in many cases this led to tragedy down the line as reality doesn't fit this simplistic theory of denial, that was the era this type of ridiculous and naive blank slate thinking was in vogue.