Or was it played up a bit?

Eg, at the start of the movie, they redid the entire orchestra because they didn't record the first run at it and Stalin wanted a copy. Would he really have executed people because he didn't get some lit tunes?

When he had a stroke in his office, the guards didn't investigate for fear of being killed. Would knocking on Stalin's door and asking if something was wrong really be a life or death decision? And furthermore, did Stalin actually die this way?

Even Kruschev, Beria, Malenkov, etc were analysing their own jokes so they didn't use unfunny material around Stalin. Would he actually have executed his own top command over something so petty?