Well, Tsarist Russia's WWI war aims centered around carving up Austria-Hungary and establishing puppet states, and annexing Constantinople. I'd imagine that, much like the Nazis took the Kaiserreich's war aims of establishing puppets in the former Russian Empire and made it "ethnically cleanse everything up to the Urals" a Fascist Russia as insane as the Nazis might well make it "ethnically cleanse everything up to the Elbe".
There was also a desire to basically get Wilsonian Armenia. Which would then have Cossacks settled all around the border. I'd say it is going to definitely be a 'first thing first' for all this, with the Russians reunifying if broken up, starting with those without foreign backers. I imagine if the Far Eastern Republic is around in here then the foreign backers of the state would actually cause the local Russians to be a bit more pro-unification, at least if their economic situation didn't improve. I can see the Russians decisions on what to do in Europe being based partially upon who acts in their favor. Might be they support the Yugoslavs or maybe they feel resentment thinking 'this is all Serbia's fault, we go to war to them and collapse and they not only thrive but they annex Montenegro'. If Russia is broken up into enough pieces and takes time to reunify I feel they might allow some non-Russian states to remain, such as Armenia perhaps. Well, if it keeps around. Might be they treat them as a little brother and use them as a partial excuse for revenge on the Turks.
So let us see... the Greeks might be acceptable, so if they stick around in Trebizond they might be kept around, so long as they swear loyalty to the Russians or form an independent state not unified with Greece. Unless they maybe get rid of the German or British monarchs. I think the Russians were fond of the Danes due to dynastic ties and mutual antagonism to the Germans and Swedes though, so the monarch playing up those links might help out. The Romanians might keep Moldavia, though efforts against Germans or Magyars might be expected, unless the Russians want those groups on their sides. Anyways, not as if the Russians would try to literally take everything up to Constantinople. They wanted the area partially for its history and partially for the strategic position that caused it to have so much history. I expect opposit that city, or somewhere in European Turkey, to be massive Russian naval yards.