Furthermore you talk of the black sea fleet. Well, Turkey, Bulgaria, Greece and Romania are all in NATO before 2004.
Are you seriously going to argue that a rejection in 2008 into NATO membership somehow dissuades Russian concerns that new leadership could change that equation? Russians do not depend on foreign actors for their security.
None of those countries listed were actual Russian territories, and calling Turkey a member of NATO that would honor its commitments is laughable. They are NATO in name only.
Finally, if you do not believe nations have strategic red lines, you have not spent a day in the industry. They absolutely do, and any possibility of Ukraine joining NATO, crosses it. Absent NATO membership, even US-Ukrainian collusion threatens the Russian strategy to (1) control the flow of commodities (food/fuel), (2) erode NATO cohesion and growth (3) create a new trading block that eliminates the dollar.
You are looking at this problem through Western eyes. Try looking at the problem through Russian eyes. You are absolutely ignoring the fact that Russia will have 15% of Ukraine next week, codified in Russian law. That is not an emotional argument. It doesn’t care about the morality of the means by which the end is achieved.
It is what it is.