The time to refuel is the time it takes for units to fly to air staging and return to where they are needed, and the cost is the opportunity cost between having your units where you need them (with less time on target) and having them staged in the rear (but fully fueled). Superimposed on those decisions is the location of air staging facilities, which can be far from the action (safe, but longer sorties) or near (dangerous, but quicker turnaround time). All of which are macro elements.
the reality is that you can't make any good and fun gameplay with it anyway considering the game we are playing
Could you expand on this?
Also "air units crash when out of fuel" is a hard no from me. That information (fuel range and time) is presented to the player with low resolution, and heavily punishing for misjudging it turns what should be a tactical opportunity for your opponent into a banana peel.