By pointing out the parlous state of the Sottish economy you are making a good case for Independence. The deficit is there because of the union. Indeed with the exception of London, Northern England, Wales and Northern Ireland are also in serious deficit. The UK as a whole is also in deficit as are most other Countries in the world. Therein is the problem with the way the UK works, as it is set up to serve the interest of London and its Financial markets to the detriment of the rest of the UK.
Unless there is a considerable transfer of power to Scotland, for example the same powers within the UNION that the UK had in the EU, then Scotland has no opportunity to change the status quo. Well run economies, run to the benefit of their own strengths can and do become successful.
The Irish Republic which whilst part of the Union was one of the poorest parts of Europe, is now one of the richest Countries in the world on the basis of GDP per Capita and is a good example. Compare its performance with Northern Ireland which remained in the Union. Dont forget it’s in the interest of any Imperial power to ensure its colonies believe they are totally dependent on the Cental Power for their existence.
For those who would point out Irelands success is only due to subsidies from the EU, that thesis has been discredited. At most those subsidies, which they no longer receive, were the equivalent of 2% per annum on GDP when the economy was delivering double diget growth.
There will be many challenges for a free Scottish state but none that would be insurmountable. In my opinion it certainly wouldnt be any more challenging than the disastrous act of self harm inflicted by Brexit!