Before the instantaneous communication of the telegraph, would it have been possible to work out the politics and military strategies of the allied and central powers in a reasonable amount of time? Would previous slower commication styles have slowed down the pace of escalation to the point that it would not have become nearly as big of a conflict? Or did the faster communication at least act as a catalyst?
Well, the telegraph was a VERY mature communication technique by the time of the 1914 crisis. There were trans ocean telegraph cables that were over 40 years old by that time (or at least, had been laid over 40 years prior), and telegraphy played a role in the Crimean War and the American Civil War decades prior. So... telegraphy is hardly new to politics and conflict by the time you are asking about.
The First World War was a result of advancements in agriculture, mechanization, chemistry, metallurgy, logistics, and a specific set of political circumstances that led key players in all major combatants to misread the risk/reward of a conflict/peace decision. Advances in communication that were now seen as status quo tech likely had little to do with the ultimate outcome.
If you had to pick one specific thing that made 1914 more volatile than earlier crises, and made the conflict more intense, you could do a lot worse than the improvements in railroad technology and the proliferation of track mileage. Without the rails, Russia can't deliver armies right to Germany's doorstep (purpose built railways with no commercial utility, financed by French loans by the way, so that certainly taints Germany's view) in ever decreasing mobilization time. Without rails, no combatant could have sustained the size of armed force in the field that they did with even food and never mind the ludicrous weight of ammo that offensives required.