I liked the 1862 scenario, and this project will be nice too!
Just
a few 
UHV proposals here...
France:
UHV1 - Shouldn't that be 1
871?
Boers:
-I just don't think the UHVs have variety if it is all defensive...
Italy:
- The "5 African cities outside Ethiopia" in UHV3 could be changed to the Western Balkans, like Albania, Yugo or Greece; Italy's main targets in WWII.
-Besides, Italy only got useless desert "Colonies" like the Horn of Africa and Libya.
China:
-I don't think UHV2 (and possibly 1) is relevant for China's goals.
-The Chinese did fight with the French in Vietnam, but they never ventured far into India or even Indonesia. They were busy with their own mess of civil wars and Euros.
Japan:
-In general, the UHVs are too concentrated in WWII IMO; and not about stuff before.
-I suggest changing UHV1 into something related to the war with Qing, Russia, or WWI Germany, such as; controlling (or keeping Euros away from) Taiwan, Korea, Manchuria, or some Chinese Port cities.
-Culture or money UHVs could be an option, unless you think they are too tedious.
-The Chinese UHV2 should replace the Japanese UHV3, since we did manage to achieve that by the 50's, although we lost the war itself.
Possible civs to add:
Israel, Arabia, Iraq, Peru, etc.... It all depends on the time frame.
Events:
A civil war event or something should occur during certain civic changes, or at least a significant stability drop.
-Russia, China, Spain, Iran, etc. could have a civil war event.
-Japan might have to spawn in 1868, or force the AI to change civics at some point, starting a civil war at around 1866. If you are REALLY picky, there could be barb Samurai spawns around 1874 to 77.
-China might be better historically, if they are cut into several civs (or just barb spawns during civic changes), since they did coexist for a quite a time.
-For example, the Qing dynasty, the Beiyang Army, the Fengtian clique in Manchuria, the Republic/Nationalists, and the Commies.
Sorry for this looong post, and good luck with modding!