Doon frae Troon
Ryder Cup Winner
Why would any country in Europe stop trading with others? The difference after Scotland becoming Independent of the UK would be that they would not have the UK free trade they currently enjoy. A trading arrangement would need to be negotiated and would probably be less beneficial than UK country states receive. If they eventually get membership of the EU which IMO is doubtful due to the poor state their economy would be in then they would trade with the UK under the same rules as other EU states. Scots would also be subject to the same immigration restraints as every other country.
For the record........Scotland does not have it's own economy. It's finances are controlled by the UK economy.