Not a single document as usual, but I'm not surprised
Stalin was a tyrant and hated his own people, but somehow he increased the population (even despite the WW2) by 40 million, he wanted to fuck his own people, but under his leadership the prices went lower and lower every April. The list is much longer.
I'm surprised you brought up the number 799455, because it's the real number of all executed Soviet people.
The percentage of people convicted of political crimes (counter-revolutionary behaviour) was 30% in average.
The highest number of GULAG prisoners was 1727970 people, which was 0,95% of the USSR population (and it was the highest peek!).
Now let's take good capitalist democratic USA. In 2020, they have 2,2 million prisoners, which is 0,7% of the population. By the way, they still have death penalty.
"So if there is already that many people in the official archieves recorded, lets think about how many there is likely outside of those and how many died not to executions but to shit conditions"
Lol not a single fact again, just conspiracy. Not surprised about it either.
About the corruption, it took place in USSR, but it was quite little before Brezhnev. Brezhnev and Gorbachev were the most corrupted USSR leaders.