Understandable, that is useful too

I believe that it is somewhat useful to focus on the USSR, since they had a lot of valuable praxis and theory which a Marxist should learn, but I agree that one should expand their knowledge to other countries of actually existing socialism, and even other non-imperialist (yet not communist) countries

It is a simple one really: that imperialism brought civilization, technology, and relative prosperity to the natives (some youtube channel that "debunked" communism said this)

I read the ABC of communism by Bukharin and Preobrazhensky, which is a concise explanation of socialist theory, application, Russian socio-economic conditions at the time, etc.