Skills effects and other things different from WC3

I think break defence -3 works like if you shoot to unit with defence 10, damage is calculated like if defence was 7. But to be 100% sure, as possibly something is translated incorrectly from Chinese or may be something works not like that was assumed to be, I'll better check it out with no upgrades, as I have 1 warhead upgrade too, which I assume just increase the attack, but possibly there is some kind of a trick like it ignores defence or something like this. So may be results without upgrades could show more.

Updated info about morale.

..great job founding that out.. I haven't got enought data from conquests to draw a graph (just some tests with lv2 ion cannon which said did 210 damage on 0 defense, 191 on 6, 188 on 7 and 181 on 10)
The rounding does not help at all with the formula, so it maybe tests wih lv4 ion or data from game files could be better
By the way, is it supposed to be linear? I think it could be x^y where y is slightly lower than 1 since your graph looks concave.
Still, great job for finding a formula easy enough to use.

Just checked, explosives have no effect to aircraft. No idea why Dowding has them, but it is like this.

Yamamoto is navy gen too, so for him explosives are ok. But Dowding's explosives made me think that they may inflict air strikes too.

Some stuff that people may not know:
If a rocket artillery attacks a foe and there's an enemy submarine behind that target, the submarine will receive damage as well. This is the only way a land troop from land can damage a submarine (it shouldnt happen though)

Burning: you can set up a tile in small and big fire. Troops and cities in that tile will suffer some damage at the end of every turn. Lasts for 2 turns for the small one and 3 turns for the big fire. % Chance to trigger it? Is the % chance affected by the type of troop that did the attack? By the damage the hit dealt? AFAIK can't be caused by air attacks nor missiles. Can be caused in any tile except water ones (kinda logical). Damage each fire does per turn?

Radiation: can be only caused by nuclear bombing, and sometimes will be caused and sometimes won't. Its similar to burning but it can be caused in the water tiles too. Even if you pick Hydrogen Bomb/Tri-Phase Bomb or Antimatter Bomb, the only tile that can be radiated is the one that was targeted. However, not all nukes seem to be able to make radiation. Tried 10 Hydrogen Bombs and none did, tried Nuclear Bomb and the second one made.. Does the type of bomb affect the chance to trigger radiation in the cell? Lasts for 3 turns, the first turn does 10 damage, the second one 8, the third one 7. It doesnt damage the hp of cities, just troops.

Cities hp: level 1 has 100 hp, level 2 has ~280 hp, level 3 city has ~400 hp, level 4 city has 500 and star city (lvl 5) has 800 hp. Edit: cities hp seem to differ depending on something, but not by that much.
If there's a troop in the city it will repair it 10 hp per turn. Edit: I gave it a go with a larger city and it seemed to be more than 10hp, maybe its a % hp, like 5% per turn?

Added info about score calculation:

Score for gens: 3000 for no gens, than as more gens you used and as better they are, as less points you get. May drop to something around 600.
Score for cities: 50 for each captured city.
Score for turns used: 1 / root(turns) * 1000000.

For 2 stars country, score is multiplied by 1.25. for 1 star country score is multiplied by 1.45.

So theoretically max score (captured all cities in one turn without gens) is (1000000 + 3000 + 9750) * 1.45 = 1 468 487