Things to fix for Japan:

the carrier Soryu and Hiryu needs rubber instead of chromium. In the production line chromium is correclty shown. I've checked all the others intial ships for Japan and the rest works fine.

at the beginning of the game, when you choose your country, you can see the Unyielding Spirit for Japan. When you play there is not such a trait.

the focus Kodoha in power doesn't give the 0.04 fascist rise. the Toseiha instead gives correctly the minus 0.01. Both focuses say in the description that they give effective changes but the changes are not effective, they modify the existing Zaibatsu trait. Effective means final/real.

Strikes event. In the description says the strikes are for the ongoing war with China so they should stop automatically if you can defeat China in the meanwhile. It does not. After the peace conference the strikes were still on and getting worse.

War with China. At the beginning the surrender limit for China is 25% but then it changes to 31%. Is it because there is a change in stability/war support in China? Is the first time I see a change in the capituation limit.

Peace in China. I finally get the meaning of the event. The text is wrong. Some provinces has NOT to be controlled by Japan or allies. That means you can annex only the cost from Beijing till the french port and free all the rest. The description of the event is written wrong.

Peace conference. If you annex all China you rise the world tension to 100%. At this point you get the events of British intervention with the international crisis and the Singapore peace conference. Brilliant idea, love it! Unfortunately at the moment is not finished because it goes nowhere. Nobody declares war on Japan and there is no downside to annex all China. There is no change of opinion between Japan and the others countries. It would be great if you can finish this. I would say Uk and USA declare war on Japan, big embargo so no more rubber and oil, and Japan gets same very bad events like uprising in china, communists guerrilla fighters destroying factories, huge drop in stability ect
It should be like France opposing the militarisation of Rhineland. The player can do it but with very bad consequenses.

Anti Soviet pact. When germany does the focus Japan gets the event, but in the event there is confusion between the anti Soviet pact and the Tripartite pact. They are two different things.
Anti Soviet Pact ( Anti Comintern) was signed in 1936 between ♥♥♥ and Ger, others followed.
Tripartite in 1940 between ♥♥♥ Ger and Ita.
In the event there is kind of a mess with Russia getting a plus 50 opinion with Japan because Japan loses anti Soviet pact and then at the same time Russia getting a minus 75 because Japan gets the tripartite pact.

Opinion of Japan with Ita and Venezuela is both +20 for same ruling party.
Opinion of Japan with Ger is +10 for same ideology.

There is no change of opinion between ♥♥♥ and Russia after the border incident focus.

Marco Polo Bridge incident was on July the 7th 1937.
In all my games the AI Japan never started the war on that day.
When I play I'm always 14 days late or 21 in advance ( if I do warrior spirit or not). Then I realized that is because I do the Nanshin-ron focus of 14 days. If you can change something you can make the AI declare war on the right date (you can shorter the Marco Polo focus from 35 to 21 days)

Focus tree.
Germany has the best focus tree I've seen so far. Lots of choices that makes you really think what is better to do next. I love all the thinking behind that. Japan tree is kind of flat. I don't have to choose much. It would be great to have the same level of complex choices to make as it is for Germany.

the focus for getting the Zero is kind of useless because you cannot do it in advance. I usually start to research to Zero in early 1939.

Naval invasion.
I'm sorry for sionprawn but the 5 capacity doesn't give any problem against the AI. It would be a different story against a human player of course

Random thoughts
Overall the Chinese campaing is fun to play. Much more interesting than vanilla thanks to forts and all the improvment of the Total War Mod. Japan is stronger than before. I didn't suffer basically any equip shortage during the war. The war was shorter thanks to the 31% capitulation limit instead of 25%. 16 months total.
I still got logistics problem when I moved inland but not much right after the naval invasions. And that's good because what kind of war is if you don't get some logistics problems ?!! It would be very boring.
Chinese army put up a good fight and seems to me that China had fewer but better divisions.

Thanks!! This is really a gold mine to me! I haven’t gotten any feedback on most stuff in ages, perks of being a small mod...