11Normandie-Niemen:
(
1st full test, v0.29, lvl III)
Excellent scenario!
'Having fixed the airfields allow us to let the correct amount of bombers take off, so up to 6 per turn... with this, "
Keep a positive land kills balance" is definitely achievable (
even if sometimes it's a little tense, at the beginning... well, the time to reduce the number of enemy bombers, that is).
-> The
Ba-65 B from the "
Remove wrecks S" trigger has to be
killed as well at scenario start... now it stays on the battlefield under some white flag...

(This may come from the fact that there is no need to change hex ownership for a recon unit.
So, having perhaps copy/past some folder...

)
-> You use the term "
Boches" two times... once in the scenario description and once in the briefing, the later very nicely like this "[...]
The Boches, as you call them - we have a less polite term - are [...]" => I suggest replacing the "Boches" in the scenario description (and only there!) by a more classical "Germans".

(
For a "first" time, perhaps don't overdo it.)
-> Consider perhaps adding something like this in the description of two secondary objectives: "[...]
Do not fall for these fakes. A careful, sharp-eyed pilot will be able to tell the difference. Destroying a fake railway gun (at any time during this battle), wasting time and ammunition and earning the scorn of our aviator peers, will fail this objective."
(As this failing mechanism works even after the completion of these secondary objectives -
'has been tested on purpose!)
*******
I've reloaded some savefiles to see stats...
Start of turn 13: already 31 enemy planes down! And lost only 3 Soviet bombers! (And it becomes much much easier to keep a positive land kills balance then...)
Start of turn 20: 36 enemy planes down vs only 4 Soviet bombers (mostly due to enemy mobile AA units)... only 1 enemy armored vehicle left to be destroyed and 1 siege mortar as well... lost a little time then to seek one last siege mortar and bring enough power over it...
End of turn 22/start of turn 23 - Major Victory! (Out of 36 turns!)
Stats:
PRI
"Destroy 12 enemy aircraft" => 36!
"Destroy 12 armoured vehicles" => 14! (Some of them are definitely much easier to destroy, as much weaker. And some of them can't be covered by the enemy mobile AA units...)
"Keep a positive land kills balance" => 19/1 (Well, once the enemy has no bomber left, or almost, and we've still many... it becomes very easy... but it was challenging during the first turns!)
"Do not lose more than 8 aircraft" => 4 (Only Soviet bombers, no Free French unit...)
SEC
"Destroy two armoured trains" => 3
"Destroy two siege mortars" => 2
"Destroy two railway guns" => 2
"Destroy four supply trucks" => 6
"Do not allow the B-25 to be shot down" => No worry, because no enemy fighter has fired a single shot at this plane!
*******
-> "
Destroy four supply trucks" & "
Destroy two armoured trains"...
Watch out! 
It's written in the description of these two objectives that "A
Yak fighter must make the kill."

It seems that it's counted
regardless whether it was destroyed by a Yak fighter or by some bomber...
->
Income? Perfectly fine, I would say.
-> Adaptations in terms of
thresholds?
1. Turns: 36 -> 30 or
32. (
I've got a Major Victory after having played the 22nd turn...)
2. Enemy aircrafts to shoot down: 12 -> 20 or
24. (
There are many enemy units in these skies... and otherwise, the focus could too soon be put more on land targets...)
-> The B-25 C hasn't been targetted at all... our Admiral is
too safe right now!
-> Sec obj, adding a red arrow pointing at the B-25 C?
Well, anyway we'll see it moving, as it's the last unit to move before our next turn, but...
-> Provide
reinforcements for the enemies:
1. When the enemy has lost a given amount of dogfighters, spawn a handful of extra dogfighters for them...
2. Exact same thing about the bombers...
3. And some dogfighter unit as well against our good old Admiral who seek emotions

(
perhaps one unit at two different times, both times near the edges of the map - very close to this bomber and the neighbouring border, an aggressive fighter purely going after bomber(s) according to its AI setup - a new AI group for this? 'This could be nice just before our B25C flies back over Kursk...)
-> A (standard, so not "personalized") event each time a Yak unit is shot down?
Just in case...