United Europe is not bad per se.
But I see several problems.
There are several historical points of power in Europe. Germany and France compete with each other, and they wouldn't want to yield. There was UK, but it seems, they gave up on this competition.
Western and Eastern Europe are not equal. I'd say, Eastern EU members have become "colonies" of Western EU members. Work migrants from Eastern EU come to Western EU for better live, but do they return to their homes? Pre-2004 EU members are a lot more equal to each other.
Unity comes from mutual respect or domination. Eastern EU members are very fond of EU because of gibs, but Western EU members are less enthusiastic about EU because they must gib. When Brussels asks about actions in Eastern EU (E-EU), E-EU members make distressed look, but when there appears Russia, E-EU members remember about European unity, because EU unity made of mutual respect lets them to behave a lot more freely (like ignoring Brussels) than latest Eastern Bloc unity, which was built on domination and didn't ask any opinions.