Russia's Army is terrible. They are a 2nd world country with nukes, which aren't even there's, left over from the Soviet Union. The more time they spend ass-covering, the less time they have for maintaining their logistical tails.
If their forward elements don't get a constant river of fuel and ammunition, they will very soon be in a world of hurt.
RE #12. Right now, I think that is the plan. NATO does not have to get directly involved, although the U.S. and NATO have to talk tough. Getting as many weapons to Ukraine as possible, let them fight, let the invasion self destruct, and avoid World War III is how this is shaping up.
I also think this is completely by accident. This is the most incompetent war the world has seen since I don't know when.