Under these conditions yes, through the mechanism of persuading German High Command to invade through the French border directly rather than going through Belgium. Without the Belgian invasion, Britain does not enter the war (or at least not so soon); without Britain in the war Germany likely does not choose unrestricted submarine warfare in the Atlantic; without unrestricted submarine warfare the US cannot be induced to enter the war on the side of the French.

As to why the direct invasion would work, we have the evidence from clashes in the field that the German armies were in general superior to the French ones, including those with defensive positions, and field experience also showed that the innovations which went into the new defenses (and the war generally) were poorly understood and inefficiently used (I have in mind here particularly the habit of radically overshooting targets and extreme underestimates of the supply requirements to sustain fire).

My extremely rough guess is that the fortifications along the border add a few days to a week of delay, with the rest of the German strategy and timetable going according to plan.

Does an "ordinary layman's understanding of actual history" include knowledge of how tanks are used in combined arms warfare to create breakthroughs in "blitzkrieg" style warfare?  Seems like "don't attack until you have tanks and a good idea of how to use them in coordination with infantry and artillery, and also don't antagonize America" is sufficient for near certain victory.

Germany should plant agents inside of Russia to sabotage Russian railroads at the start of the war. At the start of the war Austro-Hungary should just engage in a holding action against Serbia and instead use almost all their forces to hold off the Russians. Germany should attack directly into France by making use of a surprise massive chemical weapons attack against static French defenses.

I don't think that advanced tanks are needed for more efficient and more mobile warfare at that time. Just making an investment into transport for troops and supplies would be enough to hold better at the battle of Marne, or similar situations.

So I would:

• explain (with examples) benefits of mobile warfare
• explain problems with troops speed and logistics that would cause defeat at the battle of Marne
• point towards existing gasoline (possibly off-road tracked) vehicles as a solution

Introducing stormtrooper tactics would be another impactful message.

How much of your knowledge of game theory, FDT, and prediction markets/forecasting can you bring?

You wouldn't need to start with respect. People are much better at writing now than they were 100 years ago, on an instant-gratification basis. Plus, the Hobbit was 1937, I, Robot was the 1950s, Dune was 1965, so you'd be inspired by HPMOR and Three Body Problem and Hyperion while all your competitors would be running off of Frankenstein and Sherlock Holmes and Shakespeare. Not to mention real stuff like the Sequences, and the Extropian list, and what actually went down with the people involved in AI alignment from 2016-2023. 

In 1904, the world's best behavioral economist was Sigmund Freud. Most people would quickly notice what they're capable of, after having nothing to do in their spare time but read Frankenstein and Sherlock Holmes and Shakespeare.

Write an awesome book about German greatness, optimize for maximizing troop morale, but explain things well enough that most German officers can understand it. If you depict the French and British as sufficiently stupid and crude, it will probably never occur to a single British or French person to plagiarize it and use it for their own side's propaganda. It would probably get translated word-for-word and get super popular in Britain and France anyway.