Just found this thread and read it expecting the usual amount of Jingoistic bolleaux. I wasn't disappointed, though to be fair there are some excellent and balanced contributions.
In terms of defence, where would a newly independent rUK/England mount its QRA from? At a guess I'd say the sensible option would be some sort of lease operation for Lossie/Kinloss/Leauchars. Similarly for the nukes. Much as I consider them a waste of money, I'd settle for rUK/England to lease Coulport/Faslane to maintiain the subs and warheads if rUK/England wishes to spend the money required to remain part of the big boys club.
In terms of our notional sare of the national debt, fine, it's around 8% by a population basis, so I'm happy to take that on. A year's revenue from oil & gas production will soon sort it out. Failing that, we'll secure borrowing to pay it on our 8% share of the Bank of England's gold bullion reserves.
To conclude, though, a thought. Scotland's been in a Union with England since 1707. If, after just over 300 years, Scotland's economy is such a basket case, then that doesn't say much for how healthy that 300 year union has been for at least one of the partners. At least, Scotland's economy judged by UK accounting standards.
Finally, if Scotland is such a drain on England, then why not sort the issue once and for all and simply dissolve the Act of Union? Imagine how rich rUK/England would be without all those pesky Scots to subsidise and support.