Exactly. Technically they are correct, because, with no current independent Scotland, there are, of course, no Scottish banks. However, it is absurd to think that the new Scottish government, once it is formed, wouldn't have a set of well structured banking laws ready to be implemented as part of the initial implementation vote. There will also be a long line of financial interests ready to instantly start banking in a new Scotland, as soon as their chartering papers can be signed by the new bureaucracy.
The Vote No group's arguments about Scottish financial ruin are equivalent to them arguing that the streets are going to be in chaos the day after the vote, because there will be no legal speed limits, stop signs, or traffic control. The Vote No campaign is mostly financed by the existing oligarchs who are afraid they wont be fast enough and agile enough to become one of the new oligarchs.
Also, as far as movement across boundaries and access to markets, that is all part of what setting up a new government is all about, and it gets handled before formal independence and the coverage of the U.K. legal structure goes away.