Re: The democratic deficit; well I can understand that to a point, but the flip side of the coin is that democratic deficit exists all over the UK (and arguably in every representative democracy in the world). There's always people, groups or geographic areas who consistently don't get the government they wanted and voted. Should they all cede from their nations or systems of government? Where do we draw this line of "we don't get the government we want".
Even within Scotland, between 15%-22% of voters consistently voted Conservative in the Scottish parliamentary elections since it's rebirth and yet have absolutely no prospect of the government of their choice for at least generations. An uncharitable way of putting it (and I'm not meaning this in a confrontational way and appreciate that this isn't quite the point you're trying to make) is that you prefer one type of democratic deficit to another. I get why, and I get the feeling behind it. But I don't agree with it.
Well, that's a topic of some dispute

Am I correct in suggesting that you meant that independence could be some sort of lifeboat, given the following?
I think I'd dispute some of your claims there (certainly a glance at OECD PISA rankings don't agree with you), but they're not strictly germane to the point either way.
Scotland will effectively have the same starting point as the UK excluding London and will effectively diverge from that point. What I want to hear about is the policy proposals that will improve everything, irrespective of our ranking against the world, Europe or UK. And I want to believe they're achievable. And I want to see why the devolved government couldn't do whatever those solutions may be under the current arrangements.
Even if I were to accept your claims about the decline of the UK, the case has to be made on how an independent Scotland is going to be better than a devolved Scotland.