Yup, it's easy for the player to be overwhelmed by air action, so a sufficiently "zoomed out" perspective should be given. Because of its nature,air combat is very difficult to pin down the way land combat is. It is much more fluid.
As a consequence, perhaps a more "fuzzy" approach is needed.
For example,air superiority.
Every region (perhaps province is too detailed) should have two Airspace Control percentages attached to whoever is patrolling it. Daytime Airspace Control and Nighttime Airspace Control.
These percentages should not be zero-sum,but parallel,meaning that some areas aren't patrolled by anybody (Sahara?). Each nation will know its Airspace Control Percentage,but it takes air-air battles and (decryption acting as a multiplier) to realize the enemy's Percentage and to update it (fog of war should naturally impede the ability to see the enemy's Airspace Control).
The Airspace Control percentage should be a quantity multiplied by quality affair. First,a minimum quantity of planes (a wing?squadron?) should be insured for a presence to be established (percentage > 0 ), then the capability of that unit is multiplied by whatever detection means the nation has. Radar,of course,should be absolutely critical of Airspace Control. Without radar, the Airspace Control percentage should probably hover at 50-60% even with huge forces assigned at day and neglijible at night.
Airspace Control is degraded by the enemy either via destroying planes or by bombing radar stations or by having bombers penetrate the airspace,either by avoiding detection or by charging in with heavily-escorted bomb groups. Thus,the instance can exist where air control is limited even though there are enough planes and radars, but the enemy flies in heavily-escorted bomber flights that get through. This is the case with the Allied strategic bombing campaign that won by attrition vs the Luftwaffe between 1942-1944.
A special instance of losing Air Control should be enemy bombers or fighter-bombers avoiding detection and catching friendly aircraft of the ground,thus suffering higher losses.
Air Control,as a combination of presence and detection, should be the decisive factor threatening bombers, wether strategic ones attacking factories, tactical ones degrading enemy logistics or close support ones attacking enemy troops directly.
The threat can be of course,tiered, with detection more useful against strategic bomber groups and quantity,presence being most useful against enemy CAS.
As for bombing missions, a "fuzzy" system should be employed as well.
For CAS, they should be attached to a corps and fly in missions whenever that corps is engaged in battle,flying,what else? Close air support, hunting for enemy tanks. CAS shouldn't really be that useful against infantry, at least as strength losses go.
Tacs should have less Hard Attack and more Soft Attack,being level bombers and they should be assigned to either a region or an individual province assigned to logistical strikes,installation strikes or interdiction.
Strats should have either regions or provinces as strategic targets.
Of course, time of day should have a critical importance. In fact, only strategic bombing and air superiority should have any chance of success at night. Anything else should probably not even be allowed to be performed at night.
As for escort fighters,they should be assigned to as as support to bombers in the same way CAS are assigned to corps.Oh,and it would be nice this time for escorts attached to a bomb flight to actually reduce the range of bombers.
Now the problem is feedback. What does the player need to know.
IMHO, the player wants at any given time a summary.For air superiority as kill ratio would be relevant,for strat bombing a total of IC and resources bombed versus planes lost, for CAS, against a kill/loss ratio, same for interdiction.
Basically,I think the players accessing at any given time relevant,cummulated kill/death ratios for an air corps' mission in progress would actually be enough. Perhaps a pop-up graph showing the progression of the ratios over time if he desires it. Really,any relevant mission summary up to that moment would do.