4. Apparently that isn't all that needs to be said, eh?
The Citigroup quote is what it looks like from a different perspective when people say that large scale thermal generation drives consumption instead of conservation.
A carbon tax would be a great mechanism to promote renewables, but it needs to be accompanied by similar measures that remove subsidies for nuclear (such as shift of liability risk to public) and full accounting of externalized costs such as waste disposal. Since the renewables do not incur similar externalities a carbon tax that benefits nuclear is an additional subsidy to nuclear as it competes against renewables.
I was glad to see a blurb on one of the Citi analysis that I'd forgotten about - the quantification of how much spinning reserve would be required. 260MW is not a trivial amount.