The politics of Ukraine war is extremely complicate. After WW2 Ukraine got territories from Hungary (and they are still very mad because of this), Slovakia, Poland and Romania. Then Ukraine had very aggressive policies against the people from these territories and they mostly failed, these minorities speak Russian as the second language, not Ukrainian. This is not something that it is easily forgotten, people in the countries listed above still have family in Ukraine and have first hand experience of the situation.
I don't think that is an option of any sort. Wild guess is Putin bet was on Russia getting some territories opening the door for Hungary and Poland to do the same. No idea what is the atmosphere in Slovakia, but the recent surprise in the Romanian politics makes any prediction impossible. Well, he was wrong :)
That's insane. Of course it's an "option". No one in these countries (outside of a very tiny portion of wackos) cares about the current borders, or dreams of starting a war to move them.
No, full occupation of Ukraine is not an option that NATO will ever accept. With the current state of Russian military and economy, it is a very easy line to draw.
