We can almost address the situation in 2014, but before doing that, one more aspect should be discussed.

It is alliances of the nations in the reach of Russia with other nations in attempt to counter Russia's negative influence (occupation, genocide, ethnocide).

In recent history, Estonia and Latvia managed to gain their independence after WW1 in large part with the help of Britain because its interests to restore Royalists power in Russia aligned with independence war of Baltic nations against Bolsheviks. Ukraine was able to gain its independence with the help of Germany in the end of WW1. This can also explain why Baltic nations hoped that alliance with Britain could help them against Russia and why Ukrainians hoped to restore free Ukraine with the help of Germans. None of this played out but it could have if the circumstances would have been a little different.

This means that nations who consider Russia as threat are naturally looking for international players who could counter Russia's influence. Today it is European Union, NATO and US. Therefore talking about US imperialism in context of Ukraine and calling Ukraine a pawn, is malicious (borderline racist) and also idiotic.

Taking all the previous into account, it is important to distinguish between Ukrainians (either Ukrainian or Russian speaking) and Russians (ethnic Russians moved into Ukraine as part of the Russification plan).

Before 2014 Svoboda was only political power what was openly critical toward Russia. It is clear based on the elections that took place after 2012 that it was the only motivation why people voted for it. Later when they did not have such monopoly, they became irrelevant. It is not possible to deduce anything based on 2012 election results.

Without knowing what these "basically Nazi beliefs" are it is not possible to conclude anything either and that 20% is very clear minority. Azov Battalion was a multicultural battalion, it had Russian speaking majority and it consisted Christians, Jewish and Slavic paganism followers.

It is also very important to observe that Russia had already invaded Crimea in February 2014.

Before 2nd May, both Maidan and anti-Maidan supporters had coordinated their protest to avoid clashes and violence.

This changed on 2nd May when anti-Maidan militia attacked pro unity march. Vitaliy Budko opened fire from his 5.45 mm calibre Kalashnikov and killed a man. It was clear that wide scale violence was their plan from the beginning. Fighting broke loose in the city. Outnumbered, anti-Maidan militia retreated. When Vitaliy Budko returned to the Kulikovo Field, he offered anti-Maidan supporters to leave but they instead decided to barricade into Union building. Maiden protesters were not interested to attack the building but destroy the camp in front of the building. Nobody wanted to burn people alive. It was an accident, mainly caused by the people in the building who had created a complete fire hazard inside the stairhall.

If you want to have an objective idea of what really happened, I recommend you to read

An Eyewitness Account of Events in Odessa on 2 May 2014 By Sergey Dibrov
A Special Investigative Report for Radio Liberty

But it does not matter what really happened, as you correctly have identified, it was the turning point because now Russian media weapon kicked in with full force.

As in 2007, completely fabricated representation of the reality was produced. There were of course no Russians attacking peaceful march, there were no fight in front of the Union building, it was just peaceful Russians surrounded in the building and burned alive by Ukrainian Nazis (please recall what I said about Nazis). Complete fabrication of the reality. This was then constantly hammered down in Russian media. There were other numerous hoaxes like crucifixion of a Russian boy, hanging in the forest and so on. All these hoaxes were used to rally Russians from Russia into Donbas because Ukrainians did not want to fight. The narrative that was used was again the familiar one - Russia is under attack and it must be protected by attacking another country to protect it against Nazis.

The war in Donbas was not a civil war, it was a Russian invasion using hybrid war tactics.

If we remove Russia from the conflict, it will end.

Russia is the "root problem".

Lets see if you are really against imperialism or you just hate US.