Given what the British have to lose through a German hegemony on the continent, a British-German alliance simply isn't happening. I don't really see the Ottomans declaring war on Germany either, neutrality, IMO, is the most the Entente can hope for, given the level of German investment in the Ottoman Empire. I'm given to understand that the Ottoman government was not particularly eager for war, but that it also was less than fond of the Entente powers.
ETA: And now that I think about it, a Germany arrayed against A-H would probably butterfly away WWI in its entirety.
Point taken. Is it possible for a French lead anti-German alliance to become the major force on the continent leading to the British allying themselves with the Germans to stop it. Perhaps if the French and the British have a serious of small colonial incidents, maybe over Sudan or Somali. This could lead to anti-French feeling in Britain so no Entente Cordial. If the British then back the Germans over Morocco the French could start panicking over a non-existent Anglo-German pact. They start looking for allies to protect themselves. This then scares the British and the Germans into allying, the British because they are scared of the French alliance dominating the continent and the Germans because they are scared of being surrounded.
Unfortunately I can't think of a way that the Russians wouldn't ally with the French from the start, thus preparing the Germans. Also I don't think that the French have anything tempting enough for Austria-Hungary to switch sides. If the Austro-Hungarians are much stronger militarily they might consider going to war with Germany, unfortunately the necessary reforms would probably need a POD in the mid 19th century.
If this scenario did come about I don't know what Italy or the Ottomans would do. If the Italy is feeling reckless they might throw their lot in with the Anglo-Germans in the hope of getting concessions from both France and A-H, if they go with France. However if Italy joins with the French they would most likely only get colonies. Therefore I think that it would be in the interest Italy to stay neutral, on the other hand I would have said that Italy should have stayed neutral in OTL. The Ottomans are harder, and really depend on who is in charge. If they ally with Germany they could gain permanent protection from Russia and capital and technological expertise to modernise, while while allying themselves to the French could allow then to regain Egypt.
That's just my 2 cents. Sorry for the very long post and the fact that its not really on topic.