In hindsight, yes, every German from that era would have made different choices. However, at that time, it was hard to anticipate the extent to which other countries would involve themselves. The Germans of that time probably anticipated that at least one/some of the following would have occurred:

a) Serbia would give in to Austria's demands

b) Russia would not fully mobilize and commit itself so fully to war with Austria

c) In the event of war with Russia/France, Belgium would grant Germany right of passage, and remain neutral in the war

d) The UK would remain neutral in the war

e) USA would remain neutral in the war

Each of the above was a coin-toss in terms of likelihood, and if any of the above came up in Germany's favor, a long drawn out war would have been averted. Unfortunately for Germany, every one of those diplomatic outcomes went against them. Could Germany have made better decisions, with the benefit of hindsight? Of course. But I think it's unfair to portray them as evil villains, the way the Nazis rightfully are.