To put this into perspective, the Bolsheviks incarcerated and executed more political prisoners during their first 4 years in power than were imprisoned or executed for political "crimes" during Nicholas II's 20+ years.
a lot of the hell of communism was due to Nicholas's not changing -- he had a chance in 1905 when he set up the Duma. This could have channeled people's ire away from revolution to republicanism/democracy. But he subverted that. The only way for change in Russia was revolution. In contrast in the USA if you didn't like a President, you voted another way in 4 years. In the UK if you didn't like the government, you voted another way. Democracy helps to ease social pressure. The Tsar failed at that (just as Louis XVI was a failure -- why didn't the Tsar learn from history?)
Marxists assassinated Alexander II, a reformist Tsar (he emancipated the serfs). The result was exactly what the Marxists wanted: repression and stagnation under his successors Alexander III and Nicholas II, which paved the way for revolution. The greatest enemy of a radical isn't a repressive reactionary, but a moderate, sensible reformer. Under Alexander II, there was the potential for Russia to evolve into a western-style constitutional monarchy. Instead, it kept autarchy that made the most radical and violent alternatives appealing to a lot of people.
Decent fellow in comparison to Lenin and Stalin -- yes. But that's no comparison, by comparison to Stalin nearly everyone is a saint
That's about right. Under Nicholas the II, Russia was a backward but semi-normal nation in terms of its diplomatic relation to the western world and in the type of people it cultivated as a cultural elite. Under the Bolsheviks, it ceased to be a normal nation in any sense.
What you said about Alex II is true. If Alex III hadn't happened things could have been different
I dispute calling the Tsar's semi-normal -- probably lower than that, but nowhere near the depths plumbed by the communists