The only way vulching would ever go away is if people stopped upping from vulched fields, or if they gave the airfields an ack package representative of a late war german airfield - (lethal enough that you would stand a real high chance of getting shot down on your first pass or two).
And gangbanging and hording will never go away. One change I could think of that might mitigate it would be if there was an icon limit which restricited the number of icons that were displayed - so if there were say over 10 aircraft in close proximity it would only show you the nearest 10 icons or something to that effect. This would simulate the confusion of being in the middle of a swirling ball of fighters - and if you get the typical 15+ vs. 4 base attack, many of the would be gangbangers are now going to be struggling to spot their targets amongst their fellow horde members. Meanwhile the outnumbered few will still be able to clearly spot the closest threats - and it now becomes very profitable for guys from the outnumbered side to up from a nearby field and start picking off members of the "SA reduced" horde.
This would give the outnumbered a leg up (and a historical one - there were many cases were one or two fighters could score big against large disorganized formations, because the latter were spending so much time avoiding running into each other that they were bounced easily), and cause many of the gangbangers to go elsewhere - they would quickly get bored of looking at a sky full of friendlies and get bounced by guys who were sneaking up on them easily.
One thing that might make a neat addition to this would be some sort of "formation" command that would allow groups to formate on one pilot. The effect would be to remove the fellow members from the "icon limit" - the kicker would be to have this "formation" function turn off if the pilot strayed more then say 600-800 yards from the formation lead. In this way you could get an organized group of aircraft over a target without blowing all your SA - but as soon as the formation broke up for a big furball you would be back to the basic icon limit (thus keeping people from just creating one big country formation or something and "gaming" the system).
I'm sure that would require way too much coding, but it would be neat to see people actually flying in formation, and avoiding the current vulching horde technique.