The Barnett formula determines the size of the block grant, not the spending of it. The Scottish Government spends the grant according to its priorities. At the moment these include: free healthcare (including prescriptions), free higher education, and free care for the elderly.
For people not in the UK: people in England pay for each item on a prescription. The charge is currently £8.05 per item. You can get discounts if you need multiple items. There are a bunch of exemptions - people with a thyroid problem for example - which mean that about 90% of items are free.
https://www.gov.uk/government/news/nhs-charges-from-april-20...
http://www.scotsman.com/news/health/scottish-cancer-patients...
At the very least, an expansion and improvement of the existing equivalent system in Scotland (individual treatment request) would offer a better solution for the need to fund individual specific treatments that haven't been widely approved.
[Hint: they all begin with V and float]
The UK Trident submarine fleet based in a sea loch (fjord) quite close to Glasgow, the largest city in Scotland.
I'd argue that the vast majority of Scots would be in favour of re-nationalising both the railways and royal mail. In the case of the railways, I think there is fairly broad support across the UK for that too.
As Aneurin Bevan, founder of the NHS said:
"A free health service is pure Socialism and as such it is opposed to the hedonism of capitalist society."
PS: When I stayed in Glasgow for a short period about 30 years ago, a 'three way fight' in a constituency was Labour, Liberal and Communist.
On renationalisation, as noted elsewhere in this thread, the idea of taking Royal Mail back into public control has already been floated and there's support for doing the same with the railways.
Scotland is essentially a socialist country (and socialist isn't a dirty word here). There is a sense of fair play and looking after the poorest in society - a party that would propose a tax cut for a smaller gov. wouldn't do well in the popular vote in Scotland.
Does that help?