The assertion that Schukin was assasinated by the Russian Federation is unsupported. I cannot find any non-Ukrainian media that supports this thesis and I can find many that don't from third countries that are unfavourable to Russia. Therefore I conclude that the theory of assassination by a violent anti-semite is the most likely. I doubt that the Ukrainian prosecution would shy from suggesting a Russian assassination if they thought so.
I don't doubt that the nationality of Ukrainians was changed to Russians. A lot of persecution of Ukrainians happened, which is a historical fact. The question is whether the famine was intended or if it was a mistake, and it seems clear that this was not the case. Then the question becomes if it was murder on the side of the Soviet government not to redistribute food, which it would have been if they had known the extent of the famine, but as we know now the corruption and incompetence was so high that it is wholly believable that they actually thought the situation was far from as bad as it was. From then on the immigration bans make sense and so does the maintenance of exports.
Now was this on the the absolute fault of the Soviet government? Yes, it is. But so is every single famine from 1900 onwards. If you consider it to be murder, so is every single other famine since the invention of fertilizer. I only ask that one is consistent.
As for your estimates, even the Kyiv court of appeals cites a much lower figure of 3.9 million : https://lb.ua/news/2010/01/14/19793_nalivaychenko_nazval_kol... and I can find no credible source that even approaches your numbers.