You're making some valid points that no one had clean hands in this matter. It's true rivalries existed, and each side distrusted the other. The world has always been driven by people, and nations competing for power, and influence. 1914 Europe was no exception. There is no doubt Serbian Nationalism, and terrorism was regarded as a threat to Austrian interests, and ambitions in the Balkans. The Serbian State had it foreign policy hijacked by radical elements that were forcing the country to take a very dangerous course, by provoking Austria.The ongoing argument is not if the German Empire is respnsible - practically everyone here agrees that Germany and Austria were responsible for WWI. The argument is that some say only they were responsible while others argue that Russia and France did their fair share as welll to turn the conflict in to WWI. I understand how it can be confusing as some people continue to bring facts and evidence of Germany and Austria being at fault - which I personally think is pretty unecessery as nobody argues that they arent. The only reason I can think of is its a lot easier to do that and concentrate on that than looking at the french and the russians - i have yet to see any argument backed by sources instead of grand (and either unproven or proven to be factually wrong) statements of their innocence / good intentions while also repetedly ignoring the uncomfortable facts and sources the other side bring up to indicate / prove their co-responsibility. It's easier to switch the topic back to Germany (and get in to debates about minor details there) where they can bring facts and sources to ultimately prove what nobody disputes.
Russia had ambitions in the Balkans that conflicted with Austria's. They wanted Romania, Bulgaria, Greece, and Serbia to ally with them, and not Austria. They also had designs on the Ottoman Empire, and the Turkish Straits. That had been true for 200 years. Russia also kept a warry eye on Germany, ever since it had dropped it assurance treaty in 1890. Dropping that treaty had driven Russia into the arms of Republican France and created the Alliance System that made WWI possible. For its part to have any chance to resist German power France needed to standby her Russian allies and wished to cultivate a defensive agreement with Great Britain.
In the July Crisis all the great powers agreed that Sebia had acted in a criminal manor and had to be punished in some way. Russia had wanted Serbia to accept the Austrian terms to avoid war. But for Russia to accept the destruction of Serbia would mean the collapse of their whole Balkan policy and smash their credibility as a great power. That was not a reasonable course of action for Russia to take, and the Germans & Austrians knew that. The Germans & Austrians were forcing the Russians into a corner. Whatever responsibility Russia had in creating the situation that led up to the crisis is overwhelmed by the Germans & Austrians using the crisis as a pretext to start a general European war that the other side didn't want.
That is why the argument keeps coming back to who pulled the trigger on the war in July 1914. The Germans & Austrians had resolved that a general war was the answer to their geostrategic problems. The French, and Russians while prepared to fight, if forced to didn't want war in 1914. To want to spread the responsibility around may sound fair, but it doesn't help us understand what drove events to their tragic ends.