As soon as mechanization hits farming, the smallholder will not be in good shape. It's hard to raise a family on 40 acres with animals, and with the price drop from others in the same market that have went to tractors, you will get what happens all over the globe, those farmers leave the land for other work.
That's what happened in the Midwest after WWI. You needed bigger farms,to make a living at it, and that was with many belonging cooperatives that lowered costs
You are jumping ahead several steps and missing what is happening. By doing land reform, loyalty is gained from 10s of millions = less chance of revolt AND a higher growth rate in comparison to OTL.
There will be higher production rates by doing land reform in comparison to the original timeline, mechanization may give even higher rates but is not required to get higher than the original timeline.
Land reform was telegraphed by Witte and later being gradually implemented by Stolypin from 1906. There was no peacetime inclination for the Russian military or rural populations to overthrow the regime, being among the most conservative and reliable elements in the Russian empire. I daresay the first efforts of land reform were not perfect, which is another reason why such efforts are best done in a gradual manner.
No it wasent, he was giving away land where no one lived which requirers people to move away and eastablish new lives far away from everyone they knew and also futher away from potential markets to sell their products. He was not doing true land reform and the unproductive lazy land owners were still occupying the best land.
I understand the literacy rate of Imperial Russia was circa 30% around 1900 so calls for rapid democratisation of Imperial Russia are premature and verging on ASB given the leadership (not just Nicky).
My text which you replied to answers your statement
"Having a constitutional democracy where the representatives can vote and enact laws and where the Tzar can veto it unless 2/3 agree means in practice that he still has almost complete power because 2/3 of elective representatives will not agree on anything and if they do then most likely the Tzar is objectively wrong on that specific issue. "
The Tzar has practically the same power because 2/3 will rarely agree and now you have elected people actually fixing the most acute and real problems of the people, and this whole thread is if Tzarist Russia doomed, and the answer is no, if they do this and other things
Russia was already the most rapidly growing industry/economy/infrastructure in the world for decades. Imperial Russia had initiated land reforms and agricultural productivity reforms from 1906, so I don't see much of a difference from OTL. Russian industrialisation does not need more farmhands, but instead needed a more educated population. Nicky had it covered for plans for universal education, which were being implemented before the war.
Russia had an average growth rate of 3,5% per year, that does not mean that Russia can not grow more. By doing land reform and having a constitutional democracy will make Russia grow more.
The peasants who now work for themselves will be able to afford more things creating demand which will create more industrialization to meet this increased demand. The peasants will also be able to afford private schools, the Russian governments plan was full primary education in 1922, not 1918 like you seem to think, however the earlier one does land reform and constitutional democracy the faster the literacy rate grows because the now new farmers will be able to afford it and some will send their children to private schools, private schools where you pay some fee will arise by itself because some farmers will want to send their kids to school, and in addition to that those who are elected will push for education faster than the original time line.