after this protests "for eu integration" moved to protests against brutality and when police escalate more it became "ant-regime" protest
Hell, several people even made a giant catapult on-site (props given for engineering knowledge though). What surprised me at that time watching is that the Ukrainian police were so tolerant of rocks falling on them. American police would have immediately opened fire. Of-course, that tolerance didn't last long once policemen started taking casualties.
The right to protest, assemble, and even impeach representatives is just as paramount to democracy as voting. There's no rule anywhere that you just have to endure a poor leader - especially a leader who is leaning towards harming or removing democracy.
No. The ones that try to push agendas that go against their programme and are deeply unpopular will often see public protests and even general strikes demanding policy reversals or governments stepping down. Do you call those regime changes as well?
Who's going to impeach them?
You mean like "peacemaker"/"America First" Donald Trump?
> why is the solution to that problem "just endure four years of destruction until he leaves"?
If Americans can wait out for the second Trump term to be over, Ukrainians could do it too for Yanukovych.