Okay, So America is in the war, which probably means that Britain is just off the continent, not beaten. So German can do as it likes with France and Belgium, but not with Britain.
If America is in the war I really dont see how Germany could have won.
When you meet the enemy, he will be defeated! No quarter will be given! No prisoners will be taken! Those who fall into your hands are forfeit to you! Just as a thousand years ago, the Huns under their King
Etzel made a name for themselves which shows them as mighty in tradition and myth, so shall you establish the name of Germans in China for 1000 years, in such a way that a Chinese will never again dare to look askance at a German
Quting an idiocy from Wilhelm is not really helping your case for more than one reason:
1. Wilhelm was anything but consistent. Take for example this hunnic speach you quoted. On a side note of a diplomatic report a short time later he was contemplating the need of an american-chinese-german alliance to counter the british Japanese one. Than some times later he envisions in another side note the yellow menace, the horde of asians led by Japan agains Europe led by Germany. Frankly he was an idiot.
2. The hunnic speach specifically was thought throughly embarassing at the time by nearly anyone in and outside of Germany.
3. The hunnic speach concerned chinese. Today thats not much of a difference for us: they are people same as us. Than it mattered: they were not white and not christian - to the europeans of the time basically lesser humans. It was acceptable at the time to do things to them that would be unimaginable to europeans - at least before the nazis.
4. The actual expedition did nothing of the sort the Kaiser encouraged when arrived.
5. And again taking one of Wilhelms idiocies at face value and presenting it as an indicator of German evilness doesnt reflect too well on you. Every country had its loons - Germany just had the luck of one being the head of the state. He was mostly managed by less loony people.