I don't know about that -- the roots of the war had been bubbling in the Balkans since at least 1912 (the two Balkan Wars), not to mention the effects of German militarization and expansionism, and the Russian/British/French reaction to it.
The assassination was certainly a pretext for war, but it would have happened anyway. The Germans, especially, were eager for war.
yup. give or take a decade.