Along with a few others I would
LOVE to have the P-61 Black Widow. Even though I dinnae think this this bird could hope to compete in the arena during daylight. So bring on the night and the night fighters.
In talking with a squaddie he said they had tried it in brand w but it just dinnae work. Pitch black just wasn't any fun.
So dinnae make it pitch black. Just a very dark grey. Just enough light to get an outline of an aircraft at 2000-3000yds. Kinda like flying under a full moon on a cloudless sky. Even put a moon up there that could silhouette you and spell your death

On the ground add some kind of light here and there along the highest elevations of hills and have all landscape in muted greys (shadows where appropiate). This way pilots can see to avoid lawndarting. Also have the ground targets (bases, factories, etc) lit up, but subdued, so they can still be recognized and hit. Not exactly realistic, but this is more of a playability issue I think.
Icons are the next problem. Turn off all enemy icons and reduce friendly icons to 2000 or 3000 yards (with killshooter there should be a way to tell friend from enemy IMO). Only aircraft equiped with on board radar get enemy icons, and then only at 2000 or 3000 yards.
Give the night fighters some kind of readout that gives approximate range and whether a contact is higher or lower than the nightfighter. They still have to close to within 2-3k to see if it's friendly or enemy. During night time, if possible, have friendly dots on the map appear only if the aircraft is within range of an operational friendly radar structure. Dinnae really know how to deal with the ease of identification with friendly dots on the map =\
Vehicle icons could be left at 3k. The cover of darkness would also help the tread heads out as it would virtually impossible to spot them from the air, and then very difficult to attack them. This could lead to suprise "dawn raids" as vehicles drive into position under the cover of darkness. Imagine your surprise as you lift off for the first sortie of the day and an M16 parked under your runway lights you up

Just a few thoughts on the night from the peanut gallery

(of course, I have no idea of the feasibility of this

)