Even inertia had his limit and inner working of the A-H was more complicated (politically) than the actual EU and it's not a way for a nation to survive long term. A-H survived 4 years only thanks to massive German help and even in case of victory she will have not survived the following economical and social clash...and this period was the zenith of nationalism everyone wanted at least a lot of autonomy, thing that the Hungarian surely don't want as they continue their massive magyarization of their part of the Empire a program that really really really was not liked by everyone else
Nationalism is overrated. None of the major ethnic groups in the Empire actually tried to get independence prior to 1918, and those that did universally had an outside supporter of the same ethnicity. The Austro-Hungarian Empire did have an inefficient political system, and this would need to be reformed, but that reform would not be 'ethnic violence' in any of the core territories. It would be democratic, like the rest of Europe. Europe prior to 1914 was not the hotbed of nationalist hatred that it is often remembered as, it was a peaceful, increasingly wealthy, and increasingly democratic place - and that's how everyone liked it.