Ukraine never had its own independently controlled/operated nukes. The USSR deployed nukes on various territories but all command and control was completely centralized within Russia. Ukraine/Belarus/Kazakhstan returned the Soviet nukes to Russia under the same agreement and received some nonbinding assurances and cash in exchange - it was nothing like a formal pact. Had any of these countries tried to reverse engineer the nukes, they'd likely have been invaded by the US, Russia, and most other major world powers, so it was largely an offer they couldn't refuse.

Russia claims those assurances ended with the US actively advocating on the ground in Ukraine for the overthrow of their government in 2014, as the assurances included not interfering in domestic politics or using economic coercion. But the US also sanctioned and was working to overthrow Belarus as far back as 2006, so those assurances had been pretty much dead for a long time.

Outside of that I completely agree with everything else you said, especially with people not appreciating how far back these conflicts go. The whole Bandera stuff has no real parallel in the West, so I think most people wouldn't really be able to 'get it' even if they had the facts, which they overwhelmingly do not.