Have been on your forum and seen the debate about "bubbles".
Similar positive comments received in France, on the maps I've modded.
We have implemented several in Team Servers like ours ~[PuMa]~team but also on public servers to get rid of noobs and it works great.
Reg. fine tuning, had indeed to remove plane damage, to adress problem of pilot getting caught in death bubble during dog fight (especially on small maps like Bocage where you might flyby an uncapped base unintentionally during a dogfight).
Other possibilities (untested) would have been to reduce the altitude in the coordinates of the bubble (second number), to make it efficient only close to ground (the top part of the sphere only emerging).
Have finished following maps (which you have not yet done apparently) should you be interested : un_berlin (the berlin map modified with 2 uncappable bases) , and Omaha beach
For Omaha, have made Axe Tanks on beach not possible , and Axe infantery possible but only enough to block the flag (bubble line is at the level of the big anti-tank obstacles).
To do this have created 2 types of bubbles, one for vehicles (large radius) and one for humans (smaller radius, spawned 3 times along the shoreline).
Tested during 5 nights at 36 players seems to work OK, with players satisfaction 8)
I'm finishing Guadal , Kharkov , Kursk , Stalin
No plan to do Ardennes (Bulge) or Tobrouk since Tank steeling is almost part of a normal game to the opinion of lots of players on those maps.
Will keep you posted with a DL link
reg. destruction speed , I'm now using -2 for slow destruction on most maps (in 50% cases it still does explode) which is fast enough to prevent too high damage to be done by intruder.
At least, not since high school (long ago, in a galaxy far, far away). The pic of Berlin on the front page was amusing, that's A LOT of tank wreckage!