Ceasefire will solve most if not all of Russian problems.
Ceasefire will ensure
No Nato:
-Ukraine will not enter nato since there is a conflicting zone with Russia article 5 or a similar item will make all members take military action against Russia automatically so it wont happen. It is as easy as that.
-Ceasefire guarantors possibly involved Eu countries like Poland, France,Britain will be responsible for Ukranian security and ceasefire to hold.
Demilitarization:
-Ukraine will not go nuclear. NPT checks will be higher on their nuclear sites during the ceasefire
-During ceasefire Ukraine will not have anymore F16s( or other older bvr planes Mirage, F4 etc.) or cruise missiles delivered to them like Stormshadow,Scalp and Erams.
Strategic lines not under Ukranian control:
-Other than 4 regions the uncaptured areas in Donetsk can be a buffer zone(Pokrovsk,Slovyanks etc.) so not under Ukranian administrative+military control. There can be a temporary Un administrative zone in that area. Ukraine can accept this temporary ceasefire fix instead of giving these territories to Russia. This way water sources of Donetsk can be secured for Russia during the ceasefire period.
-There can be a buffer zone of 5-10+kms that Ukraine forces gradually retreat in all line of contact that inludes Sumy and Kharkiv(Russia has to retreat from these two areas for the buffer zone) as well as east bank of Kherson. Russia will ensure that there wont be an incursion like Kursk as well as continious monitoring of all line of contact by a Un multinational force.
Economic issues:
-Russia can get the frozen assets back to return to civilian economy.
-some hard sanctions like swift that hurt Russian economy can be relieved.
*The negotiations after the ceasefire does not have to begin immediately. That can put ceasefire at risk if negotiations dont go smoothly. There should be guarantees that ceasefire is not dependant on the flow of future negotiations between Ukraine and Russia. There can be a time period like 3-5 years to let things settle down and ceasefire hold. Afther that there will be a more productive environment to negotiate.
Ukraine will not accept any agreement giving up territories as they have full backing of EU and trumps tune will shift as well dont bet on him as well. The time Russia captures whole Donetsk Ukraine will have F16 free air corridor over Crimea backed by western awacs with continious cruise missile deliveries from Eu+Usa. Russia will have a hard time dealing with that. Also there is a chance that they will test some nuclear device as they have the know how and secret nuclear sites. So instead of making this frankestein any more stronger Russia can opt for putting an end to all this with a ceasefire agreement that includes nuclear monitoring and ending of western sensitive military supplies.
A possible agreement coming after negotiations later like 5-10years after the ceasefire will ensure Ukraine accept no-nato membership in a non-changaeble item of their constitution in return of the land captured by Russia to Ukraine depending on negotiations (returned lands for example Zaporizia can be administrative only and no Ukranian military presence for security reasons and gradually with limited Ukranian military presence. Maybe it will also not include strategic areas like Crimea or will include it administrative only with no Ukr military presence and Russian rights to use the ports like in the early 2000s. it depends on negotiations after the ceasefire)
Rights of minorities can be ensured with a Minsk 3 type of agreement. There will be no Zelensky after 10 years and Russian govt would possibly change as well from the Ukranian perspective and Russia will be more willing to make a fresh start with EU.