I'm not worried about the move of industries. That's already mostly happened. Industry makes up less than 20% of Britains GDP these days.
If we reduce London's dominance, the SNP can be contained. - I think this would reduce the rumblings in Manchester, but not in Edinburgh. The Scots are too far gone to stay
Is it a bad thing for the British union to end? On the whole yes, the assimilation didn't get completed, and I noticed a lot of anger in Scotland when I lived in the UK in the early 2000s and visited Scotia. It is bad for England's standing in the world, but may be it is better for England as a nation - a smaller, far less influential nation, but more sense of itself
Industry may make only 20%, but most of this is part of the European supply-chain network, so industry will decide to assemble elsewhere. Ditto for banking -- I don't see any need for banks not to move to Dubai or Singapore or Frankfurt. Barclays would probably stay, but RBS may move to Edinburgh to stay in the EU, while HSBC and StanChart would move to Singapore I'd guess
about centralization of power - People in England, on the other hand, live in one of the most centralised governance systems on earth where London decides for things at near borough-level. France is the closest in terms of this centralization