“Ethnicity Ukrainian did not exist untill 1922 when Bolsheviks had created Ukrainian Soviet Socialist Republic on territory of former Russian Empire.”
False. Ethnicity is heavily tied to language and the Ukrainian language sure as hell existed before 1922. In 1897, Ukrainian was the second most common language spoken in the Russian Empire. It was viewed as a SEPARATE language.
“Before that where known 4 closely related Russian ethnicity - Great Russians, Bielorussians, Little Russians and Ruthenians.”
Again, you apparently are not aware of just how self-aware the Ukrainians were about their own culture.
“Ukraine in many Slavik languages has meaning of borderland of no specific country. In Russian towns suburb is named okraine.”
Doesn’t matter. Cossack, do you realize how confused the origins of “cossack” is? Deal with it.
Usage of mixture of languages and local dialects is not enough to make distinct ethnicity. Dialects of Russian language in Ryazan, Moscow, Volga regions do not made locals different ethnicity. How much literators wrote in Ukrainian 200-300 years ago? Ukrainian culture is folk songs and wyshivankas, they are nice but not enough for really mature culture. Ukrainian only heroes are Benderovtsy, representatives of small group of catholicized Ruthenians who were part of Austro-Hungarian empire for centuries and annexed by Stalin to contemporary Ukraine in 1945, they were minority even in Lvov/Lemberg but they dominate now Kievan mainstream.
Cossacks is not ethnicity, it was social group, initially their main occupation was robbing. Usual way of life in old times.
Some conspirologists are regarding Benderovtsy as Vatican's and old German aristocracy's project.