NATO never promised not to expand: https://hls.harvard.edu/today/there-was-no-promise-not-to-enlarge-nato/ Ukraine has killed Russians in Dombas since Russia invaded there in 2014 as part of their hybrid warfare campaign, so yes, a long time. Russia has no interest in fair peace agreements and has said many times internally that Ukraine naturally belongs to Moscow: https://united24media.com/anti-fake/a-long-history-of-how-russia-systematically-violates-peace-agreements-1471 There is no proof that US intelligence was behind the Maidan revolution in any way. The last point is true, although the US is not an empire. Ukraine is important to NATO as a buffer zone. If Russia takes Ukraine then they will claim that NATO is aggressing them simply by having existing defenses on their own border.
You have a very biased opinion, recently documents were published in Spiegel magazine showing a declassified document from 1991 where the non-expansion agreement is in writing. Just by telling you that the United States is not an empire we have little to talk about.
And even if there was nothing signed, NATO is clearly expansionist and all NATO countries serve the interests of the United States, if this is not being an empire? I am of a certain age, I want honest speeches, I don't gain or lose anything, just engage in a serious conversation.