Re EU membership.
Apparently there are two options on this:
Scotland becomes a partition of the UK. That means Scotland would automated retain membership of the EU, debts etc would be split by population...
Scotland becomes an entirely new country. This would be entertaining in many ways. Scotland would have to apply to join the EU yes. But so would England/wales/NI as they would be a new country too. And under non-proliferation treaty we wouldn't be allowed to give nukes back to England.
All this is hypothetical of course. It is a rare event and there are not that many precedents to go on.
JollyDiane as far as I am aware assets that are physically located in a particular country will stay there. Re debt etc, I believe this is done by head of population so as Scotland has say 10% of the total population of the UK it would take on 10% of debt.
Currency. Initially probably not. Scots would retain the pound, with interest rates set by Bank of England.
Scotland would probably lose its triple A rating yes. However, thsi is the not disaster some make it out to be. Japan has, I think an AA- rating, but gets better rates than the UK as it hasa healthier economy.
Re companies, I guess they would be regulated the way they currently are if operating in more than one country (don't know what that is though).
Re bailing out banks. Under international convention, if Scotland had been independent at the time of the RBS debacle it would have only been responsible for the percentage of activity that takes place in Scotland, which I think is about 10% of the total. So not a problem.
Westminster would no longer have Scottish MPs. This would make very little difference to the overall make up of Westminster as Scotland (and Wales) have such a low percentage of population. Fundamentally, the UK gets the government that the English (especially SE English) vote for, and this has always been the case.