You are fabulous at making up arguments and then arging against yourself. My popcorn investment is safe.
I'm not arguing against myself at all - I think I'm pretty consistent. My argument being based on:
1. Not being obsessed by some mythical notion of a nation state which must be the pre-eminent level of governance.
2. Recognising that decisions that affect people are best taken at different geographic levels depending on the decision - so a decision on who to award a contract to cut the grass on a local park is probably best made by people locally, but they are unlikely to be best placed to take decisions on defence (for example).
3. Leading from 2, you want hierarchies of decision-making structures (presumable with democratic mandates) and so that the decisions can be taken at the most appropriate level.
4. That democratic decision-making structure should go above and below the notion of the 'nation-state' and actually I'd prefer the whole notion of the nation state to be blurred so that we don't see it as somehow the most important level, and certainly not become obsessed by it.
5. You decentralise and you shift power up and down as appropriate, making sure that decisions are taken at the most local appropriate level.
6. You don't centralise power unless there is a darned good reason for power to rest at that level - and cos Edinburgh is the capital of our beloved nation state is as poor an argument as cos London is the capital of our beloved nation state.
7. You recognise that some decisions are taken at a level broader than the nation state (which you've blurred anyway). So you want to form unions.
8. You try to avoid a situation where there is too big a gap between one level of democratic governance and another, or too little gap. About 10-20 times in population terms being a good rule of thumb - hence why Scottish devolution (and London devolution makes perfect sense), but an English parliament, alongside a UK parliament makes no sense at all.