To add more depth into the possible Austrian civil-war, I think neighbouring countries should be able to intervene, like in Russia. The civil-war would be a great chance for Italy to try and seize Trento and Venetia, but naturally with the risk of French/South Italian and German intervention, or possibly offer help to Austria in case of Vienna falling in exchange for land? If Russia has solved its internal problems it could send help to Austria or the rebels, and it would be a great opportunity for the Belgrade pact as well.