Well, your one didn't incorporate a lot of things that were in my head but weren't on paper until the most recent updates.
Good call on Abyssinia, Agatho.
No problem, just trying to be helpful. As Bahr Negus, by the way, the Tsar has the right to have an adviser at the Imperial Court.
Some other things that are worth mentioning is that Abyssinia has a LOT more Muslim Somalis under its rule TTL, and just holding Ogaden has been problematic enough OTL that that could lead to issues down the road. But you're right about the Oromos being resentful would possibly be more of a problem for Abyssinia than in OTL. If Demetros II was just from Gondar and no one from Yejju or Shewa manages to ascend to the throne, there won't be an Emperor with ties to the Oromos, nor a battle of Adwa to make them feel like they're part of the Empire, and they would also probably resent centralization around Gondar since it would mean a loss of prestige and power for the Waraseh dysnasty, who during the Zemene Mesafint had a position similar to the Shogun in Japan. It would be interesting if future Emperors wound up favoring Somalis so as to develop the port at Berbera and play them off against the Germans in Puntland, only for the Oromos to turn on them.
Religious differences between the Russians and the Abyssinians aren't necessarily going to be a huge issue, as they weren't a major barrier to cooperation OTL, but hardliners in Russia are going to resent what they hear about Abyssinian Orthodoxy (who, as Miaphysites, haven't been in communion with Chalcedonian/Russian Orthodoxy since 451) given some of its unique traditions, and the Abyssinian Orthodox are going to resent seeing Chalcedonian monasteries/seminaries popping up in "their" land. Russian intrigues in Abyssinian religion though might extend to getting the local Church autocephaly from the Coptic Church in Egypt. Having an Ottoman-controlled Coptic pope naming the primate for Abyssinia would not be something the Tsar wouldn't want to see.
Hopefully these ideas might help you stir the pot in that part of the world should you feel the need.
On an unrelated note, what's going on in Haiti? OTL the *Dominican half of the island was managed very poorly by the Haitian side, which was one of the reasons for revolt and eventual independence of the Dominican Republic. I still think the Spanish-speaking portion will find itself being very influential in the politics there even if the two halves don't go their separate ways. The reason I think it should play more of a role, should you have time for it, is because it would be an interesting Point of Controversy between Diversitarians and Societists, with the Societists emphasizing the cultural differences between *Dominicans and *Haitians being overcome as the reason for the island's success, while the Diversitarians might argue that the majority of *Dominicans and *Haitians were descended from the same slave population, and that the island remained stable because they were all one people and there wasn't much cultural heterogeneity there to begin with.
EDIT: Consulting the wiki and the map, I just remembered the island is now part of Virginia. That does change/explain a lot, but what is representation for Hispaniola like in the Continental Parliament? How is an island with an overwhelmingly black population governed given the number of manumitted slaves the *Virginians preferred to send off to Freedonia than to live with?