In the actual war, a German victory in South Africa was never in the cards. Because of the greater randomness created by the dice, it is possible that the lone German infantry in South West Africa could survive an attack by, say, the full garrison of South Africans (say, 2 infantry and 1 cavalry), and later march directly into South Africa. At that point, the Boer revolt is a moot point.
I recommend linking the Revolt to a German combat victory in South West Africa, or else to the arrival of a second German unit (representing, in theory, expanding military capability). At that point, the Germans might receive, say, a free casualty when attacking South Africa, to simulate the fifth columnists. That leads to other questions about how to track and apply the rule consistently, which we can set aside for now.
My opinion is that Rumania and Bulgaria should base their alignment on bids. Alternatively, you can have them align historically, but subject to specific rules that govern how they function as player nations prior to the declaration of war.
If London or Paris fall, the Netherlands would cling to their neutrality in hopes of avoiding the same fate. But, in theory, the Dutch East Indies give something for the German and Japanese players to think about in the Pacific theater of war.
You may also want to play around with the British and the Dutch. Allowing the British to attack Dutch territory in the Indies on the pretext of needing to bolster the defenses at Singapore or prevent abuse of neutrality by German and Austro-Hungarian commerce raiders could create an opportunity for the Dutch to align with the Germans.
To simulate the Russian Civil War, you’d probably have to create rules for the emergence of minor pro-Central Powers nations in Finland, the Baltics, and Poland. Then, pro-Allied Whites in Crimea, the Caucasus, North Russia, and Siberia.
Leave Italy’s alignment up to the Italian player, is my feeling.