Where would Russia have been without the Bolshevik revolution?

Fair question.

It's a commonplace to say that Tsarist Russia was as overdue for change as the ancien régime was in 1789. The collapse that took place was on the cards, and it's reasonable to suppose it would have happened without the Bolsheviks. What the result would have been is hard to say.

I'm certainly not making out the Bolshevik Revolution was a Bad Thing. I do think that Lenin had a successful revolutionary strategy but that, in terms of his own long-term goals, the revolution was not a success.

As to your second point, how to take over the political institutions of a country in such a way as not to open the field to sociopaths?