Airforce - General comments and questions

Ok, I have now finished all construction, built all of the hardware and armed it all.

1. How do I use it? It's great to have an air-force but at the moment it's as useful as a pile of scrap metal.

2. Upkeep - I will assume that we will be paying upkeep as we do for all other weapons, so what are the costs?

I think that you really have missed a couple of additional options that should be considered for inclusion in the near future. Aircraft really need pilots and crews so a flight school to train them in would be good with a possible ratio of 1 pilot per standard fighter, 2 per Advanced fighter, 3 per helicopter and 5 per bomber.

Additionally an advanced training school for SAM crews and a ratio of 3 crewmen per SAM system

I have intentionally NOT added any requirement on crews as that would make it pointlessly more complicated.
There is no upkeep cost planned.

a few days for the missions

Manleva, what you say has been considered and thought about, and pilots are logical for airforce, but they will not be implemented because they complicated the whole system without much benefit.

We will have to stick with AI controlled airforce and SAM systems for now.