1. I'm not in position to talk about that, mostly because I don't know the geography of Middle Asia.
2. Some western Siberia was conquered by Ivan the Terrible. Under the rule of Michael Romanov Russia annexed almost all of Siberia, along with some Belarussian and Ukrainian territories. Estonia and Latvia, along with some Finnish claims were absorbed into Russia after the Great Northern War during the time of Peter the Great. Catherine the Great conquered the rest of Ukraine and Belarus from Poland, Kazakhstan and the Kamchatka peninsula, along with expanding into Alaska. Between 1801-1914 Russia continued expansion, taking Moldova, the rest of Middle Asia and Finland from the Swedish, along with Volgograd from the decaying Qing Empire.
So before Siberia and Kamchatka was invaded, who did it belong to?
...Nobody. They were unclaimed lands.
Russia's history.
Siberia was never independent, just was unclaimed land. The Ukraine gained it's independence in 1991. The Baltic States where taken over a lot in there history.