No serious historian uses Mein Kampf as evidence, as it is not written by Hitler (he dictated it) and it is not edited by him, and it is made as propaganda book made to win votes.
You don't need Mein Kampf as evidence, the bizarre and belligerent history of Germany 1933-1945 is proof enough, but it wouldn't be wrong to take note of it. Ironically given his other flaws, Hitler was a rare politician who followed through with promises and Hitler's stated vision for Germany, outlined in Mein Kampf, was "expand or die". Equally obvious in retrospect is that it was a flawed and morally wrong vision.
There would not have been war in 1939 had Poland given Danzig to Germany, Germany did not want war in 1939 and both Germany and Soviet Union wanted strong Poland between them to slow down enemy attack. And remember Molotov-Rippentrop pact never was agreement that would split Poland between SU and Germany, it was agreement to put Poland under their Sphere of Influence. But things went differently.
You're right that the German leadership did not want war
with UK or France in 1939, but if Poland had given Danzig to Germany war would only have been postponed until sometime in the 1940s. It depends if Paradox wants to script events for a short-sighted and pacifistic Great Britain and France.
This idea that Germany would've left Poland to the Poles if only they had given up the Danzig corridor is very misguided. The programs Germany implemented in the early 1940s for expansion to the east are profoundly disturbing and would fall under forbidden topics on this forum. But whatever they were, they weren't improvised after 01 SEP 1939.
Adam Tooze's "The Wages of Destruction"
Probably the most illuminating book on World War 2 I've ever read.
Germany in 1939 had 99% employment and its industrial output became 2-nd largest in the world slightly behind USA( in 1933 it was 8 places below).
This is not so remarkable with German economic planners, with the power and control of a police state, overheating the national economy in preparation for an imminent war.
Its military machine was gearing, with German High command projection of optimal time to develop army will need to wait until 1943.
By the time of the Molotov-Ribbentop Pact, Germany had to go to war (or partially De-mobilize which is rather unthinkable) or it's infrastructure would've fractured not long into the 1940s. Hence the initiation of Operation Barbarossa
in June 1941 while the British Commonwealth was still alive and a threat.
Today ,under expertise that is, is a home movie filmed by Eva Braun in 1939 that seems to show the moment Hitler received diplomatic reply from British that they will not allow Danzig to be returned to Germany.
Hitler was furious. Movie is silent, but lips-reading experts discovered he said something like: "Idiots, do they understand this means Disaster for all." This will imply Hitler at least at the time of Danzig was not ready to start war.
I can't speak to the truth of this specific anecdote, but it seems to me to indicate that Hitler wanted to avoid fighting the Western powers for as long as possible in order to fight and defeat an isolated Soviet Union first.
To get away from the name calling, what do you guys think realistically would need to have happened for Germany to make a deal with poland and invite them into axis? If continuing to beat the war drum against communism could they perhaps tried different expansion routes?
The Nazi Party being overthrown. To use an EU4 analogy, asking the Nazis to abandon Lebensraum in Poland would be like asking under what circumstances Spain abandons colonization of the New World.