Probably there will be a lot of tension/hard negotiation regarding Poland (that want out of Russia whatever the type of goverment and i personally doubt that they will trust anybody from Petrograd/Moscow with promise of autonomy as already being burned by the Tsar badly) exact border and the Baltic (at least Lithuania).
Poland's borders (and Lithuania's, too) are indeed a difficult question. This is not just a matter of international negotiations; it also depends a lot on who comes out on top in the inner-Polish rivalries (both within established Polish parties and between armed factions). IOTL you had Pilsudski who pushed Eastwards to fulfill his dream of a big multi-national, Polish-headed "Intermarium" empire (PLC-resurrection map-wise), and the Russian Civil War made this a promising route for a while, and you had Dmowski and his NDs, who looked to a Westward expansion at Germany's cost because they favoured an ethnically more homogeneous Polish nation state. Politically, Pilsudski pushed (and then abandoned) the socialists to whom he belonged until the end of the war into an expansionist policy, and when they wouldn't follow, he went his own ways (terminal station: Sanacja), then there were countless agrarian factions, and the NDs of course. It is quite true that neither Germany, nor Austria-Hungary, nor Russia are viewed by many Poles as anything other than hostile powers, but the question of who is the lesser evil is answered differently by them, and this answer shifted over time as the balance tilted. When A-H broke apart, the successors weren't quite as pro-Polish as Pilsudski had hoped, but that was already predictable.
ITTL, the situation is different already by now. Ukraine is not a nascent sovereign nation state plagued by civil war, there is no peace and demobilisation along the entire front, German Ober Ost is still very much there even if it has instituted a few more puppet governments. There are Polish Legions all over the continent in different camps. The Germans uphold a "Regency government" which is quite as unpopular as IOTL. So, inner-Polish developments are going to be just as exciting as international hagglings about it.
The Romanian gold, as well as the second train's load of more immaterial value, are still safely kept in the Kremlin. Russia and Romania are allies, in fact, in spite of misgivings about Brest-Litowsk, Romania is one of Russia's staunchest allies.
Speaking of the future, a socialist russia as a member of the entente and international community and not perceived as the first stage of the world revolution, can also mean a lot less trouble in the immediate postwar, with all the revolution and border wars, at least in Italy this will mean that the moderate lead by Turati will be stronger of OTL and that will have a lot of butterflies at the socialist national congress in september 1918 and the immediate postwar both in economic and social term
I am still unsure about the PSI. I tend to think that the Maximalists all together are at least as strong as IOTL as a consequence of TTL's Russian Revolution, but their internal divisions might be even more pronounced. Also, I wonder which "moderate" Russian socialist leader Turati will look to for inspiration - Fyodor Dan, the Menshevik whose staunch Defensism could be said to have been proved right by the course of events and German intransigence? Iulius Martov, the Internationalist Menshevik parliamentarian, who is still not quite convinced about the war effort and who criticises the Kamkov coalition for what we'd call "violation of human rights" today? Someone from the former Menshevik "Bread faction" of Skobelev, who, driven by the inner dynamics within the trade unions and urban soviets, combines more radically anti-capitalist economic measures with a continued support of the defensive war effort since November? Or someone else from among the Unifiers? Also, I wonder what lesson not only the Italian socialists, but also other socialists across the world will learn from the first socialist revolution succeeding in establishing its own federal state being led not by one of their parties, but by an agrarian-populist party? Kamkov, the actual head of the Russian state, leans very much to the left, but he is an SR, not a member of one of the RSDLP splinter products, but of a party whose roots and traditions lie in Narodnichestvo. Kamkov himself is not an agrarian romanticist, he is from the party's urban, ultra-pro-industry wing and one of the architects behind a coalition of the SRs with as many groups from the industrial labour movement as possible. Yet, he is still an SR - the party has not split ITTL -, and the most fundamental reforms enacted both by his predecessor (land reform) and himself (urban housing "reform") are not focusing on socialising the "means of production" (although empowering the soviets has allowed this and this has occurred here and there), but on redistributing immobile property. Not an easy role model for socialist labour leaders...!
When we come nearer to September 1918 and the background of events against which the party convention happens have become established, would you be interested in covering TTL's party convention in a newspaper article of your own,
@lukedalton? (I'm sure
@Betelgeuse wouldn't mind looking over it language-wise, too.)
Oh, and before I forget to address it:
World Revolution!
This concept is present ITTL, but it has not yet taken on the notion it did by September 1918 already and even more so by 1919.
The conviction that the overturning of capitalism by the proletariat cannot be a local or national phenomenon, that it has to be necessarily a worldwide phenomenon in all developed capitalist countries, is not a Leninist idea, it is Marx's and Engel's own. Such a staunch World Revolution-Internationalist position can be found in socialist parties in almost all countries by 1917/18; in many of the larger parties, it is a minority position, sometimes of a strong, sometimes of a more isolated fringe minority.
What this means, and what it has meant IOTL until 1917, too, is
a) the theoretical assumption that capitalism is a global phenomenon which, when it collapses, collapses on a global scale, and
b) the practical conclusion that local proletarian action should be coordinated as much as possible across the world so as to help each other in the way most conducive to causing the ultimate breakdown of capitalism and the building of a new society.
IOTL, after the Bolshevik coup, the humiliation at Brest-Litowsk and the intervention of the Entente in the incipient Russian Civil War on the side of the Whites (whatever its main reason was - hoping to bring Russia back into the war on the Entente's side, or eliminating a danger to capitalist bourgeois democracy, doesn't matter: the effect on the Bolshevik psyche went with the latter), "World Revolution" very specifically meant protecting the Soviet Union and undermining those who conspired against it, and then the Left splintered and splintered, with some continuing along this Muscovite interpretation, and others replacing it with other notions, more and more theoretical ones really.
ITTL, "world revolution" is still very much a hot topic among socialists in 1918, but while it does carry notions of "supporting Russia", "Russia" is not equivalent with a total systemic transformation, nor with a pacifist exit from the Great War. That makes it complicated for socialists in Entente countries: should they hope that their country's government's war effort against the CP is successful because this would give Russia a chance to build its new society and support revolutions elsewhere? Or should they continue to protest against the war, sabotage it, because it's an imperialist war and because their government must be brought down first if they want socialism in their country, too? So, practically, "world revolution" becomes hotly contested even within those who favour it, while theoretically at least, imperialist capitalism does appear like it's on its last legs in mid-1918, with even the Entente governments having taken control over vast sectors of the economy in order to gear it towards a smoothly running war economy, with debts piling up so high everyone knows they'll never be paid back, with so much destruction caused, confidence among the labour movement growing that they couldn't possibly do a worse job running their countries than their bourgeois governments even if they tried, with hunger and diseases spreading like it's the last days of the world described by Revelations...
So, while I expect the Internationalist Left to debate quite intensively throughout 1918 (there will be articles documenting it), interesting changes of opinion might also occur among those whom the former like to call "Revisionists", both among the Right and the Centre within the socialist movement. Kautsky is on the way out either way, so the Centre is reorienting, and the Zimmerwaldian "Peace without annexations or indemnities" formula might soon become replaced by something else. The Right, advocating parliamentarian reform and unionist negotiations, will be watching events in Russia with interest, too (and not just with horror, like IOTL), and all those favouring national over international perspectives will not only follow the federalisation of Russia closely... if Austria-Hungary is collapsing in any way even remotely resembling OTL in 1918, then what happens there is going to be highly relevant to their worldview, too. (After all, not only the horrors of the Great War, but also the post-war hagglings often with socialist parties in coalition government fighting against each other was what made explicitly nationalist stances a rather isolated position within social democracy in the course of the 1920s, even if the Komintern's internationalism was also anathema to them.) And as of April 1918, Austria-Hungary is looking even weaker ITTL without Ukraine, even if not quite as overstretched as IOTL.
Wait, why are the British blocking their own allies from shipping food to their other allies? Did they lose their mind and declare war on the rest of the Entente when I wasn't looking?
I don't know what
@Karelian thought about here, but the British sea blockade caused high risks even for neutral or friendly shipping and created costs (for convoying) and delays (for British inspections), too.