"There is still an ongoing debate on whether Scotland would need its own currency immediately after independence. I am baffled by this. The answer is yes if Scotland wants to really be independent. It's as simple as that."
The ability to control the economy through the issue of money and through tax. The ability to regulate banks. The ability to control interest rates. The ability to support the economy with QE. These cannot be done if a country relies on and uses the currency of a different country.