This is not something Russia have reach on, I mean, what stop Jan Stoltenberg tomorrow say, "Now I will bend all the rules and accept Ukraine membership without every country in NATO agree"? I mean, that is highly undemocratic but that can be done, so is US and UK and some core European members form another NATO like binding organisation and invite Ukraine to be part of. Russia also cannot have anything to veto that. it's not UN, and we are not talking about Security Council.
Whether or not Ukraine will join NATO or a NATO like organisation is beside Russian point, Russia can say no to negotiation, but again, that will come back to who want it the most. Judging by the fact on the ground, Russia is the one retreating, and Ukrainian is the one that advancing at the moment, again, would Ukraine want to talk about peace now??
This is much further than Russia pulls all the force off Ukraine, the war did not end there, because the trust between Ukraine and Russia is completely gone, in a political and diplomatic sense, it makes no sense for either side to stop the war right now unless there are incentive to do so, and the incentive of both side is in direct conflict with the other side, that's the thing to consider here.
Again, you are missing a very obvious point. It does not really matter if Ukraine were able to cede their land, that is not the primary issue here, the primary issue here is Ukraine don't Trust the Russian, which mean even if Russia say tomorrow "I am going to withdraw from Ukraine" that does not end the war there, because it does not guarantee Russia will not come back for round 2. You can cede anything to Russia or don't cede anything for Russia that does not matter for the Ukrainian. Because peace with a rifle next to you all the time is no peace, if Ukraine want peace, they will need to either snuff Russian desire of invasion, or have Russia no longer become a threat. The second part is ALWAYS NOT ACHEIVEABLE for the Ukrainian because the Russian have 6500 nuclear warheads, which mean conservatively, Ukraine needed is not Russian boots off Ukrainian ground, Ukraine need is a security guarantee that Russia will not be able to do it again, or at least have to think twice before they will do it again. If this is not met, there can be no settlement, because there can be no peace, then why bother to settle.