I think Scotland would fare O.K if she became independent. GDP per person is high, skills are there, Financial Sector is there, and they are well placed to trade when independent.
For various reasons I do not think that 2020 is the right time to hold a Referendum, not least because I think the result would be close, despite what the Press may say,and Social Media pundits.
Once the real debacle of Brexit has begun to bite, then it will be the time, and I say good luck and all the best to our Scottish friends. England would not like it because they would slip behind Brazil on the list of Countries GDP per person.
There are alternatives,real devolution of power, not some half-arsed attempt at one.
I back Proportional representation of some sort for the whole of the U.K, if that came first, Independence as an issue may fade. I will not hold my breath, the Evil Tory Racist Government just elected by a broken system, would not stand a chance with P.R of getting a majority, so will resist it to the last.