Right Jess I'll do my best but you would get more authorative answers if you put the questions to Alex Salmond next Tuesday. The oil - International Law applies - all Oil and Gas fields currently in British Waters are subject to British Laws, rules and taxes the boundaries are agreed and recognised by all adjoining countries, such that any new field can be easily determined to be in British or Norwegian waters, etc. If Scotland becomes independent of rumpUK, (England, Wales & NI - I call it WINE for short
) then everything in Scottish Waters is Scotland's everything in WINE waters belongs to that country. Approx. 90% of UK oil fields are in the sector deemed Scottish. At present Scotland benefits from around 9% of total revenue as its share on a per capita basis because around 9% of the UK population live in Scotland. David Cameron, or any future PM has no say in this matter. 30+ countries have won their independence in recent history so there are precedents for how the division of debts and assets will be decided. If no amicable arrangement can be reached then the (International) Courts will rule - just the same as in any divorce.
In very simple terms there will be a net gain to the Scottish Exchequer because of the enormously increased income from oil revenues and the decreased expenditure i.e. none, on weapons of mass destruction. Of course there are a myriad of other items in the budget to take into account but the effects of the 'big two' gaining and saving billions in both cases will ensure that Scotland is better off on its own.
Scots at present are Brits and members of the EU. Scots pay income tax & NI, VAT, Road Tax - all the taxes at the same rates, by the same rules as those living elsewhere in the UK. We DO have Tax Offices in Scotland you know! staffed by fully trained personel some of whom will have contributed to writing the software, which belongs to, is owned by, ALL of us in the UK. Same goes for military bases, equipement, ships, aircraft etc. Given a split Scotland would be entiteled to 9%ish of all UK assets and (unfortunately
) liable for 9% of UK debts.
Opinion polls consistantly show that the majority of Scots wish to remain in the EU, while the majority in the rest of the UK want to leave. No country has ever been ejected from the EU and I cannot see why the EU or United Nations would reject a civilized, resource rich and oil producing country when they have extended a welcome to the former Yugoslavian and Russian states. With Cameron's referendum on the EU in the offing we might even see in 5 years time WINE out and Scotland in! We live in interesting times do we not?