Why? The EU is looking to more than just tax financial transactions, they are looking to even outlaw short-selling thinking they can support the Euro and their economy that way. Brussels cannot get it through their heads that if you prevent people from selling, you will prevent people from investing.
Scotland would be entitled to the North Sea Oil. It could actually end up with a surplus budget – one of the few around in the world. It would also be interesting but separating from the UK would disrupt the bond markets for the question would then turn to who get the debt. Traditionally, it belongs to the UK and if Scotland leaves the UK it belongs to England.
If Scotland were to recognize that being outside both the UK and EU would act as a magnet for capital if it does not join the paranoid Anglo-Saxons respecting privacy then this could be a real economic boom. They would be clean or past problems with the banks regarding Germany and the USA so you could actually have a real banking system emerge that once existed in Switzerland.