Near the top left hand corner is an icon that looks like some paper money. If you cursor over it, you get your current positive or negative Percentage Number for inflation/deflation. This seems to work thus:
base money cost x Percentage Number = an amount of money
This fractional amount rounds off to the nearest whole number value. This value gets added to the Money cost of the element, but not to the Conscript Companies or War Supply cost. So, if you have no CC's or WS, then it won't matter if you have 100% inflation or deflation. Normally, WS is the CSA's bottleneck and inflation or deflation of the money supply isn't a concern.
Your interpretation of the combat power numbers is correct. If you cursor over the icon of an arm flexing its muscle at the top of the Combat Power column in the Nations Comparison table, then you get a menu explaining this.
I'm the 51st shade of gray. Eat, pray, Charge!