I don’t have exact statistics for the first question at hand, maybe someone here does. That’s a great book by Parenti by the way

On the last question, it’s true that the vast majority of people in socialist states wanted socialist relations to continue. A lot of people at the time wanted to see progress and change, but not to actually change the socialist mode of production. Propaganda promised them a better life with all the fancy and shiny gimmicks the west had, but they weren’t told that this would come at the expense of everything they considered a given. The wide and free access to quality healthcare, the right to work, the guaranteed housing and basic necessities that everyone had simply because it’s a human need, were all taken for granted after so many years.

The reason I’m pointing out the erosion of pure socialism from within, is that this is the material background in which the collapse came to put the final touch. The capitalists had regained too much power, the west started having more influence, contradictions were arising because of this blending of socialist and capitalist relations, and because of all that it came to its weakest point. This should be researched in much more detail than I’m able to give without doing research myself, but it’s a general sum up. It’s both wrong to conclude that the USSR fell solely due to the western sabotage attempts, and it would also be wrong to conclude that it fell because socialism “didn’t work” (despite the ridiculous amount of evidence showing that it not only worked but created something never seen before for millions of people that previously couldn’t even read and became the number one competitor to the USA). The answer lies in between.