There nothing in your post with which I would disagree.
Wrt the Crimea, the Russians fought a war over it against the British, the French and the Ottoman’s justifying their involvement as protectors of Christianity. But you probably know all that.
The Soviets created the Ukrainian state.
The Russians conquered Crimea from the Tartars in the 18th century and it has been populated by ethnic Russians ever since. As you pointed out, Crimea was put inside the Ukrainian SSR which was a mere province of the USSR in the early 20th century.
So, are we supposed to find if there are any Tartars left?
The Soviet Army lost nearly 600,000 men in defense of Ukraine in WWII.
And the Russians have nearly that many buried in Crimea from all the wars they fought there against damn near everyone.
How can anyone reasonably say that’s not their exclusive sphere of influence?