It hasn't been agreed that Scotland would be a successor state because the negotiations haven't happened yet. Scotland has every right to be constituted as a continuing state. If there's something I've missed can you link to it please?
My mortgage is with Santander, and like everyone else who already has a mortgage in Scotland, I already have a contract, and it's tied into the BoE baseline. Nothing that happens in respect of international borrowing rates for Scotland is going to have any effect on that.
However, the money markets will not penalise Scotland because if it is a successor state it will have no debt and be running a surplus, even if Scotland does borrow at a slightly higher interest rate to begin with, the country will be running a surplus so it will in all likelihood be absorbed.
Far MORE WORRYING is the situation for the rUK, which will be running an annual deficit which will have gone from 4% up to 7%, and has a housing bubble which is comparable with Spain. It's the rUK that's the economic risk, and losing the security of North Sea oil backing up the pound is why the money markets are twitchy (thought the fall in RBS shares is perfectly within the median range over the past 12 months)
I really hope that someone can back with some answers to my big questions on the UK economy -which I'd say are far more pressing than any questions about how Scotland might operate. The UK exports less than it imports and has a massive asset bubble in London property - that's exceedingly more likely to crash and in doing so, ruin the entire UK. Isn't that a bit more worrying than an extra couple of percent on borrowing for new mortgage holders, in a country where the value of houses hasn't gone up in real terms since 2007?
We need answers about the UK, whether independent or not, we ALL need answers about the UK...