If you want to blame anyone for the horrors of the war I would say Conrad van Hotzendorf

 I would say Austria as a whole, along with Russias poor leadership at the time, and i would say Germany gave Austria to much power (The whole "Blank Check" deal) However, Germany and Russia did not want war, it was a serious of catastrophic mistakes that led to WW1, in all the nations i just mentioned.

but the Germans did commit serious war crimes

The German Government, as a whole simply did not, the only War Crime the army actually committed was to an extent, what is claimed to have happened in Belgium (It did happen, but it was NOT anywhere near what the Brits claimed) and that was not the German Government, but rather a few misguided officers, much like the time the US massacred a village in Vietnam (I forget the name of the incident) it was not the US, but a few officers that let it happen.

Plus the British and French didn't attack civilian ships with U-boats.

 The Germans made it quite clear that any civilian ships in the area where in a war zone, and even gave the ships warnings to turn around, and the ships where by no means "Civilian" you stop being a "Civilian ship" when you smuggle arms and food into a country, knowingly, through a war zone, even Lusitania was carrieng weapons. and as a matter of fact the British did sink civilian ships, not with U-Boats but with warships, the Germans even made special Cargo U-Boats (The Deutschland class) to sneak past the British blockade. its funny you never hear about the brits blockading Germany and starving millions, but you always learn about the German blockade of england.