As for the NATO discussion, it’s absolutely true that it’s not some kind of benevolent force for good in the world and I don’t blame Putin if he feels threatened by its Eastward expansion. But while it might be used to intimidate Russia, NATO wouldn’t start a military conflict between the two. The bigger threat, I believe, is the expansion of Western control and ideas. If Ukraine, a country so closely tied to Russia, becomes fully “Westernised” then perhaps Russia could be next. Ultimately that has to be Ukraine’s decision to make though.
NATO and EU enlargement is directly related to the fact, that from the Eastern European perspective, Western integration is just more beneficial than being neutral or being in Russian zone of influence. We can relativize anything we want, but we've been (as East Europe) in Russian/Soviet zone for +40 years, and Ukraine even longer, I think that's enough for Russian to convince us that cooperation with them has its benefits if they have anything to offer. They couldn't do it, because FR is too weak.
The effect is that we've been feeling threaten (let's say Central Europe and the Baltic countries) by Russia since '91 and we prefer Western integration, and this is why this discussion about NATO-threat is kind of theoretical. And that is why majority of Ukraine can dream of being in a situation like Poland, so ~60% of Ukrainians are for EU membership now etc. Russia may feel threaten not because of a possible military attack of NATO (lol), but because Russia will lose against West on normal conditions because of combination of political and economic reasons, that is why Kiev is bombed. And this is what's this conflict is about, really. Check out Polish and Ukrainian GDP PPP in 1991, and in 2020, we were at 6,7k$ in GDP PPP per capita in '92, Ukraine was at ~6,4k$, we're at 34k now, Ukraine is at 13k (IMF data), that is why living in Poland is a major progress for average young Ukrainian, even though our parents started at the same level. And the same with our security. There were many variables, but first and foremost - we integrated with the West really quickly, Ukraine hasn't yet.
And what's really paradoxical is that they'll be eaten alive by China in a longer period of time for the same reasons, yet they unaware that this alliance is only temporary, in Central Asia they already have problems in countries like Kazakhstan to be as influential as in the past.