One question that was actually fairly difficult to find the answers to on MSM and their associated search engines was - what were the deals that the Russians (Putin) and the EU offered to Ukraine? Because, ultimately, that's what sort of started Euromaidan.
(I'm going by memory here, I haven't looked up the figures recently, so my memory might be off!!) The EU offered an $800 million *LOAN* and for the government to impose a range of austerity measures, the likes of which plummeted Greece and Portugal into recessions (and heavy debts). Russian offered a lot more. Also, if Ukraine sided with the EU, they'd lose the benefits of cheap Russian gas (amongst other trade - remember that Russia was Ukraine's biggest trading partner).
So - economically (at least short term), the smarter option was to keep the trade relations with Russia.
IIRC, the EU vetoed continuing trades with Russia, while Russia did *not* veto trades with the EU (just like... Belarus?? Or some other former Soviet Union country which manages to stay in between).
There's also the 'movie' out there by Oliver Stone that sheds some light on it - including who some of the Euromaidan players were - very much pro-US people! Ukraine got played!
Also, Obama should have accepted the election results - here he is talking about what "the people want" - yet there was a democratic election held (whether you accept the results or not is a different matter).
Yanukovych seems like he wanted to play both sides (and as president of his country, I'd suggest that's largely his job!) It *appears* as though Russia would have tolerated it, but the EU and IMF wouldn't have. Cold War II mentality. (It's what i've said elsewhere - the US (in particular) has wanted to keep the Cold War alive and well, and when the wall fell, Russia should have been granted access to the EU and become a realistic trading partner - but that would make the US lose out, and of course, NATO needs a big scary bear to justify its MIC role)
(https://www.reuters.com/article/idUSBRE9BI0E2/ for more information)