Why then did they invade Kharkiv and Kyiv?
Russia invaded neither city, nor did they try real hard. They threatened them in order to pull Ukrainian forces from other areas which they did intend to keep. Of course Russia would have been happy if Ukraine would have surrendered since it would further one of the goals. Namely 'de-nazification'. But they never put the forces together to win these cities militarily against a determined adversary. They, and every other competent person can see this.
Why did they level cities in Luhansk and Donbas?
Moscow studiously avoided doing so when practical in all areas, but most particularly the one's they plan to incorporate into the federation. Kiev wasted a lot of ammo trying to do so in Donetsk, and still does for reasons known only to the NaZiocons. You'll have to ask them, but I would suggest that expending ammo on trying to kill civilians detracted from their ability to fight Russians and contributed to the generally poor performance in terms of logistics and strategy.
Why did they level Mariupol?
To get rid of the Nazis. Next question?
Why are they bombing apartment buildings in Kyiv, Lviv, or Odesa?
Generally they avoid it unless there is a high-value target. Most of the time when a seemingly benign civilian target is hit, it's traced back to errant Ukrainian air defences. Of course Ukraine and the Western propaganda always say 'Russia did it', but their proclaimations are completely without value to anyone who is somewhat infomed and observant. They will always say the same thing, within minutes, no matter what the details.
It is obvious what they want to do. They want to annex the whole of Ukraine and kill anyone who is not agreeing with it.
It's obvious they don't, and they would only do so under extreme duress. It would not 'accomplish the mission' of de-nazification anyway since the West would absorb the Nazi-types as 'refugees' and keep them busy with operations like the 'Charleston' hoax.
Do you think if they take control over the four oblasts that they already 'annexed' on paper that they will not want to go and annex Odesa and Moldova? Of course, they will.
At this point, they very well might. The economic and strategic value will make up for the reparations that the West obviously won't be paying to Russia.
They are Nazis and they want to exterminate Ukrainians.
Very possible that they are generally on-board and in bed with the WEF and Talmudic and designers of this whole engineering effort. I cannot rule it out.
Their plan is to slowly grind Ukraine and Ukrainians into ashes.
What's very very amusing is that the geenyuses in the U.S. were dead-set on turning Ukraine into a quagmire or 'another Vietnam' which would sap Russia and they were positively gloating about it. In reality it turned into exactly the opposite. Russia is doing quite well on the world stage (in part because most of the world is sick of Western bullshit and only stick around for the bribe money), and the 'collective West' is bleeding out at an impressive rate.
I suggest that the WEF types knew this would happen and welcomed it. The Talmudics running the U.S. most likely as well. Some of the low-level Neocons (e.g., Jake Sullivan) may well have believed the bullshit that he had a hand in creating. That's why to real powers install not-very-bright people into fairly high level positions.