Problem with Nicky is that he isn't prepared, but he showed signs of being an enlightened despot.
He is obviously interested in modernization, economic development, industrialization, improving peoples conditions. Like what he did otl. Insurance to workers, healthcare, education funding industrialization via French loans. Building infrastructure. Problem being Russia is so big
I mean, if Nicky is prepared to take throne. Russia will be good under his reign.
Nicky being an enlightened despot is the best case here . An Enlightened Absolutist. The Duma was dysfunctional so ineffective and inefficient that Nicky had to iotl bypass the Duma just to pass needed laws and others such as military modernization to have funds
He must be a strong and fearsome character like his father Alexander III
Being meek when he should have been fierce didn't help
He could have ruled until 1960 if he had a more powerful, decisive and intelligent personality
Most important of all, he changed his personal life
(Anyone, even a Japanese or Ottoman princess, would be much better than Alex of Hesse seriously
(Wilhelm's sister Margarethe would be suitable as wife to Nicholas)
Make him more inclined to listen to his mother and moderate members of the family and avoid reactionary members
(Maria Fyodorna had some good advice like reducing rusting, but ignore her ferocious hatred of Germans.)
Make him less affected by the court factions and make his word the last word, whether the court or his family like his father
(His continuing to improve his relations with the Ottomans as his father did was a clever thing, but supporting Serbia against Austria was a complete folly)
And most importantly, he must be smart
(Supporting Japan's proposals for influence over Korea and Russia over Manchuria would be a smart thing because it would drive the Japanese away from Britain and bring them closer to the Russians instead of underestimating Japan.)
Abandoning France in favor of reviving the League of the Three Emperors would be a clever thing
(If Nicholas uses his brain, he will realize that he will gain nothing from antagonizing the Germans, since his cousin is German, and he is half German himself, and it is the French who will gain, not him)
(And the Balkans, which betrayed Russia several times, does not deserve the blood of a single Russian man)
(While the approval of the Turks can give him freedom of transportation and an economic preference for his country and cut Iran between him and them)
And imitate your cousin Willie and grant concessions and rights to the workers and pay attention to the latest developments, but do not give a constitution
He downplayed the nobility and appointed men as skilled in their work as Stollpin (his surviving his assassination would greatly help Nicholas)
Repeal Paul's first laws
(Alexei is a nice boy, but face it, he won't live long, your daughters are the ones who will survive, and you don't want to give your throne to your cousin Vlad, so repeal these stupid laws)
Things like this can guarantee a decent Nicholas II (not very smart but decent and not a moron in OTL)