Ukraine is not what u think it is. It should've been divided along the Dnieper River into two different countries after the Soviet collapse. And yes Crimea belongs to Russia.
USA deliberately poked Russia to start this war. The goal of the USA is to whittle down the strength of the Russian military. Can't have a regional power in Europe.
Only the USA can have a Monroe Doctrine. Nobody else.
Rewarding their actions can delay them, but at the cost of strengthening and replenishing them, which creates bigger future problems.
Appeasement is a bad strategy: https://en.m.wikipedia.org/wiki/Appeasement
Neither side in this situation want peace. The Ukrainians want their country back and don't want to be ruled from Russia. They were going to fight whatever happened and if Russia had quickly established control we would see civil unrest. Russia isn't interested in peace their whole leadership is invested in this war.
We know that the US tried to settle things before it started and Russia was incoherent. https://www.bbc.com/news/world-europe-66509180
I don't think Russia is interested in peace, given that they can already achieve it unilaterally. And if one party doesn't want peace, I don't know what the US can do in this situation.
How do you have peace with a country that doesn't abide by the peace agreements it signs when it's not convenient for them?.