Looks like you covered all the current Russian talking points here. The US (and NATO) are fighting a proxy war against Russia using Ukrainian troops in order to kill as many Russians as possible. Russia is fighting to keep NATO off its doorstep because NATO is simply a massive conspiracy to attack Russia. The war keeps going because, and only because, the Ukrainians won't "negotiate".
Putin has very clearly, and on many occasions, said that Ukraine is not a country. He thinks he's entitled to own it. So Ukraine is fighting for its existence. Even if Ukraine agreed to allow Russia to keep what they have occupied so far, Putin would not let them be a sovereign country. He claims that they are part of his "sphere of influence", an obsolete 19th century political term, which Putin believes should give him extra rights. Since he would never, in any negotiation, allow Ukraine to join NATO, they would become a Russian satellite, which next to outright annexation is what he has stated he wants. Your "argument" is the same one that the powerful aggressor always makes. Think of the widows and orphans.
NATO/US is not and has never been interested in attacking Russia. (And NATO is already on "Russia's doorstep" in any case). What NATO/US wants is to keep Russia from attacking whoever they want. Russia is a declining economy. If they want to become a world power, they are going to have to do it the normal way and create a world economy.