United States of Greater Austria

Franz Ferdinand was reform-minded and would probably let the Imperial civil service do what it will, and hopefully avoid war.

You're right; a liberalized Austria would not stop an aggressive Germany.

And with the way the German Empire was going, they would find a way to drag everybody into a major war.

  I don't know about that.  If Austria is even neutral it means that Germany's position is far weaker.  No Austrian forces to tie up the bulk of the Russian forces while the Germans try and crash through Belgium.  No Skoda super-heavy guns to smash the Leige forts that quickly.  No real hope of allies in say Bulgaria or Turkey as their going to be way beyond German support.  Also without Austria's fleet, such as it was, and basing facilities the French can take over some of the channel defences while there is unllikely to be any U boat activity in the Med.  Which greatly improves the allies economic situation.

  I think its unlikely that German would risk something alone and if it did, even if the Haber process is in place I doubt they will last more than a couple of years at most.

  Steve

  Romania wanted lands from both Austria-Hungary and Russia, but mainly the former so its attitude might depend on what Austria was doing.  Also early in the war, while much of the country was pro-allied the king was pro-German, being a member of the Catholic branch of the House of Hohenzollern. 

  Bulgaria, presuming the Balkan wars still occur as OTL [which isn't certain] has alienated itself from Russia and has serious greviences with Serbia and Greece.  However as the 2nd Balkan War showed it is largely encircled and has bad relations with Romania and Turkey as well.  [If there is a different trigger to the conflict, say from the 1st Balkan War, then you might see all the Balkan states on the allied side and Turkey with Germany from the start but many options here].

  The Turks may feel friendly to Germany and did have additional links  but if Austria isn't allied to Germany no other minor power is likely to side with it which means Turkey would be very isolated once war began and would have great difficulty getting many materials  to support its war effort or even its peacetime economy.

  Possibly the best bet for Germany is that either Austria is hostile/neutral so its the 1st German target, which might also bring Romania in against Austria, as they want Translyvannia.  This could of course mean that Germany stays on the defensive against France and Russia while advancing through Austria which might make an alliance practical for Turkey.  It may not be too bad for Germany as without an invasion of Belgium Britain might stay neutral and has the French and Russians showed in their 1914 offensives against Germany that is a very costly operation for the attacker.  Alternatively say Austria is fighting an Hungarian rebellion but then Romania is likely to be fighting the Hungarians.

  It would be a likely ally for Germany against Austria provided that there weren't other major powers supporting Austria, most noticeably Russia who wanted to restore its influence in the Balkans and get closer to the straits.

  I think if we're assuming a break between Germany and Austria we need to consider the circumstances, especially if its one that leads to a shooting war between the two.  The most obvious POD might be that if Germany scaled down the nationalism a bit [and to a degree also Russia its pan-Slavism] then Germany chooses Russia rather than Austria.  However I think it unlikely once Wilhelm gets to the throne and drops the pilot.  

  If it occurs at a later stage, say to F-F succeeding FJ say ~1910 then a lot would depend on how various factors work out, such as how alliances change and factors such as the Balkan Wars.  By this time the Franco-Russian alliance is pretty strong and both are concerned about German power and intent.  [And vice versa to some degree].  Therefore I would suspect any war would be Germany v France, Russia and possibly depending on circumstances, Britain with Austria seeking to sit it out while it reforms.  This would be pretty grim for Germany and other than a verging on suicidal move by Turkey I can't see any clear allies.  [Unless the entente between Britain and France/Russia had soured for some reason in which case Japan might be tempted to have another crack at Russia, although this would be pretty risky now the Trans-Siberian is fully completed].  There is the possibility Austria might be dragged into a wider conflict due to either Hungarian rebellion at the reforms or hard line pan-German feeling seeking to 'restore' the alliance with Germany and assist it but either are more likely to lead to civil war in Austria rather than massive foreign intervention as everybody else will be fully involved in the main conflict.

  If for any reason Germany and Austria gets into a conflict without either Russia or France supporting Austria then both Romania and probably Italy are likely to be German allies.  Mind you Germany v Austria without any allies on either side is pretty grim for the latter unless its some way down the line and reforms have given the Hapsburg empire considerably improved economic and military power and social cohesion.

  Steve