Second question first, naturally. Yes it should be allowed to. All peoples should have the right of self-determination. Obviously this is pretty difficult in some cases - look at Israel. Israel is made up mostly of Israelis, but it also contains loads of Palestinians, so it's very difficult to decide who should rule which bits. How do you decide which bits of a country to treat differently in a referendum? You can always just let everyone vote and then different areas get to go to whichever country they voted for in greater numbers (see the Schleswig plebiscites) but would the rest of Scotland want to be an independent country without, say, Edinburgh? Luckily for Scotland, it is a nation. Most people in Scotland consider themselves Scottish, some also consider themselves British. It is not, luckily, a Yugoslavia style confusing mix. Therefore, an independent Scotland would basically be a nation-state, which is a fairly recent phenomenon but nonetheless seems a fairly reasonable basis for a country. As such, a referendum in in Scotland would be a simple matter of either the whole country staying in the Union, or the whole country leaving. Hopefully.
You can get as many lawyers to look at it as you like, but I think this is a pretty clear cut case of a nation of people who deserve the right to become a state.
So now, secondly, the first question: Should Scotland leave the Union? Well, that's complicated. Firstly, let's assess the situation with sentimentality taken out of the equation. Would Scotland be viable as a state? Yes, certainly it would. If you're worried about it's size then Ireland has a smaller population and they're doing ok..... Well, maybe Ireland is a bit screwed but that's because of economic mismanagement not because they're small. And yes, I'm sure Alex Salmond is perfectly capable of mismanaging the economy but that's a reason not to vote SNP, it isn't a reason to be against independence.
How about more practical considerations: currency, border controls, foreign policy? Well, actually, Alex Salmond's view of an independent Scotland would make all of that pretty easy. Crossing the border would be just as easy as it is today, they would still have the same currency, and we wouldn't have to move any armed forces about (or any members of the Royal Family, come to that). Basically, Salmond simply believes that Scots themselves should have the power to collect and spend taxation from Scotland, in Scotland, as they themselves see fit. Bailing out the banks is often used as an example in discussions on independence, because Scotland would not have been able to bail out RBS alone. This is true, but these banks have massive UK interests, and Scotland would be a full member of the EU. As such, I don't think there is a huge amount to worry about on that issue.
If we take into account tradition, then we would look at the fact that the Union dates back 400 years. Tradition is worth maintaining for the sake of tradition, but only when there is not a better option. When I started writing this post, I believed that I would come to the conclusion that whilst Scots should be allowed to hold a binding referendum, they should vote no to leaving the Union. Actually, I have come to a very different conclusion. For as long as the rest of the UK and Scotland can forever be the best of international friends; for as long as the independence does not throw up new problems of currency and borders; and as long as the transition is slow (as Alex Salmond wants) rather than abrupt (for logistical reasons), I support it.
Though I am genealogically English, I spend most of the year in Wales. I enthusiastically consider myself British, and I value the country I live in as Britain. However, I think that Scotland has much to gain from greater autonomy, and if that means being a separate sovereign state, then go for it. I support Scottish independence.
