It's fairly obvious that the people running the EU have a vague long-range dream about some sort of Union of European Socialist Republics--only nice, of course. National pride and sovereignity tend to get in the way of this sort of thing.

I have no problem with nations or states combining into some larger organization--I live in such a place myself--but in recent history almost every plan for such things has been proposed by rabid collectivists, and it shows.

Has anybody ever proposed a European Union with severe limits on its own powers, and an emphasis on the rights of states and individuals?

Something to watch for: a GOOD constitution or treaty will almost always be quite short. I believe the Treaty of Lisbon is about 250 pages long, and consists mostly of amendments to two other treaties.