Did Stalin ever nominate his own successor (USSR)?

Answer 1

No. Nikita Krushchev gained the leadership after a power struggle. After Stalin's death, Lavrenty Beria took power. Fearing for their lives, Georgy Malenkov, Lazar Kaganovich, Vyacheslav Molotov, Nikolai Bulganin and others, united under Krushchev to get rid of Beria. Malenkov should have been the heir apparent, but Krushchev eventually took the party leadership on September 7, 1953. He became Premier on March 27, 1958.