On the other hand there is difference between theory and practice, you can have any ideological system, but if you depend on totalitarian dictator everything can fall apart - You depend on mood of that person/party.
Just guessing ;-)
Bullshit.
That the hatred is on the much more versatile axis of class instead of race doesn't make it any less vile. You don't rack up a 20th century record of a bare minimum of 100 million slaughtered without exercising a lot of hatred.
You also need to consider what class means. It's basically behaviour: you are upper class if you exploit others. In that lens, it becomes ok to hate the upper class, but the upper class can change, it's not hated based on something inherent to the people that make it up, like "race".
Communism: kill millions of poor people for their politics.
Fascism and communism are the same thing, if you define them by how many poor people they torture and murder.