Man, anticommunist leftists sure love ignoring the political, historial and material context of things, don't they? Yeah, Lenin was evil and he did that all because he was very very bad and the Bolsheviks are so evil!!! The man who consecrated his entire life to a worker's revolution, read and wrote extensively about it, and from the start was adamant on educating the workers through newspapers and other publications, just was so bad and so evil and so bad. Bad Lenin! Bad!!
If by "nothing required the overthrow of the results of a democratic election" you ignore the ever-increasing threat of a reactionary, pro-Tsarist coup under lukewarm administration, then yeah, it wasn't required.
If by "nothing required Lenin to purge other fellow socialists" you mean there weren't counter-revolutionary Mensheviks and other such assets in positions of power during a literal civil war, then yeah, it wasn't required.
If by "crushing syndicalism" in Russia you mean not immediately giving the means of production to uneducated workers, but instead slowly growing unions to unforeseen levels of participation, with tens of millions of union members in the 30s already, but understanding that socialism can't survive against the onslaught of external powers without heavy planning (as proven by the 20+ million soviet deaths in WW2 in the fight against Nazism due to still comparatively low levels of industrialization), planning which initially can be done better by a vanguard party of socialist intellectuals, then yeah, it wasn't required.
If by "crushing the working class" you mean creating unforeseen levels of access to healthcare, education, eliminating unemployment and homelessness. Or maybe you mean going against the interests of Kulaks and understanding that the best for peasants isn't direct ownership of the land, but the elimination of structures of ownership of it altogether. Then yeah, it wasn't required.
Talking of war communism as if the USSR wasn't facing constant struggle against the rest of Europe portrays that you either don't understand the history or you're making a malicious intent. The Bolshevik revolution faced a coalition of the Tsarist loyalists in the civil war, which was militarily and economically supported by a total of 14 other countries, including Britain and its colonies, France, and many other European powers, in the direct aftermath of WW1. It's basically a miracle that the Bolsheviks were able to win the war, and it speaks very highly of their power to mobilize the population and resources in times of extreme difficulty. This was in the immediate inception of the newborn state, before the USSR even existed as such. Then it was subjected to economic sanction and isolation. Afterwards, during several attempts to make agreements of mutual defense against Nazism with France and Britain (and even Poland) for all the decade of the 30s and being systematically ignored, what is the USSR to think about the rest of the world? Again, the victory of barely post-feudal agricultural USSR against the industrial power of Germany which was established for more than a century at that point, is basically another miracle. Saying that the USSR didn't have reasons to see itself in "war socialism" is astonishing. It falls into what Michael Parenti said in his work Blackshirts and reds: for anticommunist leftists, the only worthy revolutions are the ones that failed.
This is not to say that there weren't excesses in repression during the USSR. Of course there were. Stalinism was extremely excessive and brutal during WW2, and the oppression went way overboard. Then again, that's the nature of the history of states up to that point, isn't it? How can we expect the people born in brutal systems of oppression, who directly suffered that oppression, to not fall in excesses of oppression when times are hard? The best we can do is analyse these excesses from a historical, materialist, constructive point of view, and try to minimise the excesses. But let us not deceive ourselves with idealism: revolutions are bloody, and the ruling class doesn't give away its power without fighting. Let's learn from the mistakes of the past and build more fair and resilient systems that won't commit those excesses, or will minimize them. But let's not be ignorant about the historic and material conditions that led up to them, or we will fall in the same mistakes, or even worse, be on the receiving end after the reactionaries take over.