“Rule from Brussels” would mean having an independent vote in the Council of Ministers (the ultimate decision-making body), including - as you acknowledge - a veto over key decisions, including any further treaties as would be required for further institutional integration. As opposed to no effective say at Westminster unless they happen to be holding the balance of power.
Not that I would want the UK to break up, but if anything makes it more likely, Brexit does: especially if argued from a basic misunderstanding of how the EU works.
That logic is pretty strained IMO. Only in a highly exaggerated ‘leave’ view could anyone equate the degree of control by the national (and highly centralized as countries go) UK govt over all of the UK* to the much lesser degree of control by the quite weak Brussels ‘government’ (if you can even call it that) over EU states. Denmark is no more an independent country now than Scotland (two places with similar size populations) because Denmark is an EU state? That would be a pretty ridiculous statement IMO.
If Scotland voted to leave the UK it would become an independent country in a loose federation of countries, as opposed to being part of a (very real) country now, the UK.
Not to say Scots should have (or should again if it arises) necessarily voted one way or other all things considered, but that’s a real difference in sovereignty.
On OP’s theme, I don’t agree with the logic much either. OP keeps saying they accept the idea of non-zero sum relationships…but then always go back to ‘OK maybe it’s not zero sum, but who benefits more?’. Once you accept the idea of non-zero sum, it’s irrelevant ‘who benefits more’.
If I’m a Scot who contemplates the arrangement from a strictly Scottish POV, I needn’t care how the rest of the UK benefits or not from Scotland being part of the UK or not, only whether Scotland (or myself as Scot) is better off inside or outside the UK, in tangible and intangible ways. And if I’m a Scot who emotionally views myself as British, I simply vote to stay. If some combination, I fight it out in my mind and decide how to vote. In no case is it directly relevant ‘who needs whom more’.
*less so Scotland since devolution, and even other elements of Scottish autonomy long preceding that, but still.
Which they very obviously aren’t. I have no opinion on whether or not Scotland needs England; I do have opinions on interpreting referendums.
So first, while the side that said “Yes” likely feels that they don’t need England, the side that said “No,” can have a number of feelings, anywhere from “yes, we need England” to “I don’t know if we need England,” to “we don’t need England, but we really don’t need the hassle that leaving England will bring.” So, it isn’t like the majority of votes cast were for “we need England” just a plurality that didn’t say that that they point blank didn’t.
Second, even if we were to assume that a “yes” vote does mean that voter thinks
Scotland needs doesn’t England, and a “no” vote means that the voter thought that does, I have doubts that the electorate (even a highly informed electorate) really knows what the country “needs.” People on both sides could be very, very wrong on a specific axis or just wrong altogether. (financially? culturally? militarily? ____) democracy doesn’t get you to truth, at best it gets to people’s perceptions to part of the answer to the part of the question they care about, and people are not good perceivers.
The claim that membership in the E.U. amounts to a surrender of sovereignty equivalent to Scotland entering the United Kingdom is propaganda. It’s a false statement of fact. It’s also consciously false. It’s a big lie constructed to fool the public into jingoistic nationalism and short-circuit any rational decision-making. Like the kind of thing that Trump does every day.