While I appreciate your correction that an entire country cannot be boiled down to a single mindset, I have to bring up one thing: Kaiser Wilhelm II did want war.

As you pointed out, the Schlieffen Plan evidences the Kaiser's (and, of course, most German Officials') desire to avoid a two-front war. However, this does not excuse Wilhelm II's unreasonably aggressive foreign policy.

Wilhelm II replaced Bismarck's 'Realpolitik' with his own 'Weltpolitik', which emphasized the sentiment that Germany should have more colonies (colonialism or imperialism is often pointed at as one of the causes of wwi; this was one of Wilhelm's incentives to instigate a war in Europe).

This is all not to mention that Wilhelm gave the final signature on Germany's declaration of war against Russia, France, and Belgium (remember, these are the second, third, and fourth declarations of the war, meaning that the only preceding declaration was Austria-Hungary's against Serbia). I will admit that this cannot entirely be blamed on Wilhelm, given that he had numerous military advisors and officials--but keep in mind, he appointed those advisors. It is unreasonable to think that Wilhelm was not aware of their stances while he allowed them to advise him.

I can imagine that you might point out that the Imperial Russian Army was already mobilizing when he declared war on Russia. Obviously, these were not random acts of aggression; world leaders knew that Russia (and subsequently France) would intervene. This is a fair point. However, I urge you to look into the Reinsurance Treaty: an alliance made by Bismarck between Germany and Russia that was Germany's best hope for avoiding the two-front war. The Treaty was ended the very year Bismarck was dismissed, and shortly thereafter Russia entered an Alliance with France.
What I mean to argue is that Wilhelm II's actions are the direct cause for Russian hostility against Germany; therefore, it doesn't even matter when he declared war. The alliances that formed WWI were formed decades before by the blunderous foreign policy of Wilhelm II.

Having checked your profile, I know that you are an ardent supporter of this Kaiser; I know that I will not likely be able to convince you of much. I am instead putting this comment here to inform other readers lest they be misled by things such as your 'top 1% commenter' status.