It's gunna be a mess. For starters, only Scots who currently reside in Scotland are allowed to vote. If "yes" wins, expect to see a huge push for a revote including all Scots, not just the group most biased towards independence.
The only plan for a currency is "we'll use the pound" which is not a plan at all, since the remaining UK will have to vote on it, and politicians supporting a currency union with a newly independent Scotland will face political suicide with the rise of nationalist parties.
The SNP has no plan for a military, other than "we'll have one, and we'll be in NATO." I think the last I heard was a standing army of 3,500. As compared to the UK army of 100K.
The UK nuke enterprise is heavily embedded in Scotland. Independence will be the best weapon of the anti-deterrent crowd, since moving nukes to a new place is political suicide.
As it stands, Scotland uses a larger portion of public funds than it supplies in taxes. The NHS is already at the breaking point in many areas.
The SNP plan appears to be almost entirely supported by the idea Scotland has enough gas and oil to be like Norway, but unlike Norway, Scotland's oil wealth is based on surveys of future reserves and extraction potential.
I think they have a decent chance of winning the vote. I also think that if they do, it still won't happen, especially if Whitehall keeps to their promise of denying a currency union. A revote including the many, many Scots who live in Wales, N Ireland and England would also kill the movement.