Rescues have been raised before. I think they're a good idea - it'd be useful to include Grasshoppers, Storch and that British high-wing STOL plane - I forget what it's called now.
Also, in previous threads we've had the idea of a truck or C47 being able to drop an 'Airfield Engineers' package which creates a very small airfield, able to handle fighters only. These need regular re-supply to stay active. They don't have radar and they don't appear on the map unless a recce plane (Mossy, F4, Ar-234 etc.) takes a picture of them and then a 'marker' appears on the map for about 20/30 mins.
This recce idea also works with CVs, where the recce plane 'photographs' the enemy fleet and the marker appears on the map but is stationery, and lasts only 5 mins. This might be a justification for some maritime planes; PBY, Condor, Short Sunderland etc.