Yes. Yes it does!
If it's a spring shotgun(which i assume it is) then the weather will not affect it. If it uses gas, then yes.
The color of paint does not affect gas mileage in any way.
Yes, the faulty power steering pressure switch does affect the gas mileage. It will give a wrong reading of the gas mileage. It is therefore important to fix it when it is faulty.
Yes.
If it is malfunctioning it can affect fuel mileage.
You can play airsoft in any weather. Airsplat.com has Ghillie suits and vests to keep you warm in the cold so you can play airsoft at anytime of year. Check out Airsplat.com for airsoft accessories and guns.
yes
YES YESYESYESYESYESYESYES
incorrect tire inflation
the lower your rear axle ratio, the worse your mileage.
All of the engine sensors can affect fuel mileage.
Yes.Yes.