I feel like updating my Russia-Ukraine analysis:
1. Russia still requires that a peace agreement be made with some serious "trust and verify" guarantees; they will not accept something that leaves the door open to attacks on Russian territory.
2. Russia will want freedom of movement for Ukrainians, in particular those who seek to defect to Russia, but is less likely at this point to demand restrictions on immigration into the Ukraine as the territory becomes increasingly depopulated.
3. Russia still wants the disputed territories and will not concede any of them, even the ones that are currently under "temporary occupation," precisely because they believe they can take all of them. Zelensky will likely use this point of negotiations as a major sticking point, as a dispute now exists between Zelensky-defined and Russian-defined boundaries of the disputed Kherson Oblast, with the Zelensky-defined border being a very small area surrounding Kherson city on the Zelensky-controlled side and the Russian-defined border extending further inland, and Zelensky also claiming part of the Russian-controlled Kherson Oblast as part of their official borders; this is an area Russia will certainly not cede both due to its territorial claim and its military control.
4. Despite buffer zone bluster (such as former President Medvedev posting a picture of the entire Ukraine except two cities as a buffer zone) Russia will probably be willing to accept a more limited buffer zone, such as 10km of the border, as a more pure guarantee of peace.
5. Russia's military situation is extremely favorable and in the long term they stand to annex the entire Zelensky-controlled zone and achieve the ambitions of those hardliners who advocate complete Russian unification. Putin is only holding back in hopes of good trade outcomes.