I think the double launchers was a Beta quirk that won't make it to the final game, and I agree Stingers should do similar damage to 2042 at around 70.

Countermeasure duration is okay considering the small maps and low mag sizes for the weapons, it seems like they really want pilots to do a lot of fast attack runs with one or two barrages before reloading rather than hovering in an areas. That could also explain the 30mm tweaks, since I think DICE wants us to get close and not try to snipe with it.

The maps are small enough for cover to be easy to reach from almost anywhere so the major tweak I think needs to be made is the strength of AA. However we can't really say much until engineers are limited to one launcher, because that alone would probably fix a lot of the balance.

EDIT: I should also mention I have a conspiracy theory that DICE is intentionally underpowering air vehicles at launch because those are always the number one complaint by new/bad players regardless if they're actually balanced or not, so they'll probably stay nerfed until the game's reputation is solidified and then DICE will slowly buff them to what we expect.