Ukraine

Nobody should. But it is an election year, and the price of oil is an international concept, so if you burn a gallon in Moscow then a gallon in a swing state gas station costs more.
Maybe, but Ukraine is fighting for their survival, targets of Russian infrastructure that allows them to prolong the war is fair game, or it should be. If we as a country can't support our allies in spite of a couple of dollars per gallon of gas, then we aren't very good allies.

Regardless, I don't think loss of Russian oil production is going to affect prices that much. The world is already living mostly without Russian oil exports at this point.