The government is representative...of what? What does it represent? Saying "the government is representative" is not a complete sentence, pretty much like saying "a capitalist economy is efficient" without saying efficient at doing what.
Representative of the persons or organisations chosen by voters at an election. It might be possible to imagine a more "representative" way of doing things, but the Bolsheviks did not achieve more; they attained less, than what is meant by a representative parliamentary government. I have no special definition of my own, of that expression.
Oh and I don't tend to dismiss struggles, I do tend to dismiss social/economic/political structures which I find problematic.
That is a very serious mistake, and one that I would have expected you to avoid. Problems are meant to be examined, not dismissed.
The Constituent Assembly was irrelevant at that time, it had no authority anymore. If you're looking for the point where the Bolsheviks destroyed the Russian revolution, consider their take-over of the soviets instead.
No, it was strangled at birth. I don't know if the Soviets could have survived without powers and procedures defined by a constitution. Their destruction by the Bolsheviks is related in my link, and was subsequent to the dissolution of the Constituent Assembly. Here is the wiki account.
Instead the socialists ... hoped that Soviet re-elections would go their way once the Bolsheviks proved unable to solve pressing social and economic problems. They would then achieve a majority within local Soviets and, eventually, the Soviet government, at which point they would be able to re-convene the Constituent Assembly.
The socialists' plan was partially successful in that Soviet re-elections in the winter and especially spring of 1918 often returned pro-SR and anti-Bolshevik majorities, but their plan was frustrated by the Soviet government's refusal to accept election results and its repeated dissolution of anti-Bolshevik Soviets.
So all democratic assemblies were forcibly dissolved, parliament and Soviets alike. As I say, the perpetrators of this criminality didn't realise the mortal danger it represented, to the Revolution and to their own persons. Later, under the firm hand and stern mind of comrade Stalin, they understood their mistake, but by then it was too late for remedy.