You would be wrong. The people you described were called "тунеядцы" in USSR. With a possible exception of bureaucrats who existed as a result of centralized government but were also called "a barrier for the working class" by Lenin etc.

I also highly doubt USSR would accommodate people who move in and don't bother to integrate into the culture and speak Russian. Ask people from entire countries where Moscow did Russification, and those people didn't even move in from outside they already lived there.

The trial of Joseph Brodsky is a fascinating insight into the workings of the USSR https://www.nytimes.com/1972/10/01/archives/the-trial-of-jos...

They had strong opinions of what was deemed "socially useful" work and were not above abolishing those pursuits they deemed to be useless.

All able-bodied people were expected to work (in approved roles) and you would be provided a job if you couldn't find one but if you refused to work they would deem you a "social parasite" and prosecute you if you didn't reform your behavior.

Somehow, people seem to forget that Marxism is an ideology of workers.