>>The carnage for the Russians has now hit well beyond anything they ever anticipated.<<
I don't doubt the Russians have suffered some painful blows, but the maps show that it is the Ukrainian forces that are in near constant retreat, with Severodonetsk and Lysichansk being the most recent examples, with the latter apparently via a rushed retreat.
That said, I think the Russians vis-a-vis the EU will do what is best for the Russians, and I don't see how destroying their own FX-earning pipelines is in their self-interest. At least not at this point in time.
As far as inflicting real pain on EU, I think there are three items of note. First, most of the pain the EU has suffered to date is self-inflicted. Second, Russia seems more than happy to finance its war by selling NG to Europe at exorbitant (spot) prices. Third, I think Russia will absorb its (war) losses and continue to play the long game against Europe, meaning Russia will do its best to redirect critical exports (metals, fertilizers, grains, NG, etc.) away from Europe, thereby leaving Europe weakened, divided, energy-shy, and with much of its industry decimated. As to how much of that can be said to be self-inflicted pain on Europe by Europe and how much is due to Russian retribution is beyond my pay grade.