I expect these to be developed "from each according to his ability"
1) Collectivization & 5-year planning & ending of the NEP start 4 years earlier than, in 1924-
How might this happen. But even more importantly, assuming it did happen, what are the medium-term and long-term effects? Is the USSR better or worse equipped for any mid-20th century brutal military-industrial competition? Any economic ripple effects abroad?
2) Collectivization & 5-year planning & ending of the NEP start 4 years later than in OTL, in 1932-
How might this happen. But even more importantly, assuming it did happen, what are the medium-term and long-term effects? Is the USSR better or worse equipped for any mid-20th century brutal military-industrial competition? Any economic ripple effects abroad? Do people end up attributing the decision to launch then as much to the Gold Depression as to founding ideological concepts?
3) Stalin dies between September 1938 and May 1941 of sudden natural or accidental causes (not assassination, not an act of war, not a coup). How does the succeeding collective leadership or single successor
Vozhd perform in charge of the USSR in comparison to him? Is this as much of a disaster vis-a-vis foreign enemies as Stalin himself and Stalin fanboys would like to portray?
4) AHC: USSR adopts NEP-like policies within 30 years after WWII
5) Soviet Union sends Red Army across the border to support the KMT-CCP United Front in 1925-1927. It's quite precocious of course, but what happens fro there.
6) Soviets invade China more broadly in 1929 railway war
7) Soviets intervene against Japanese occupation of Manchuria as it happens in 1932-1933
8) Soviet-French military cooperation or Soviet-British or Soviet-Japanese or Soviet-Italian or Soviet-American military cooperation in place of historic Weimar Reichswher military cooperation
9) AHC: Soviet leader as thin and athletic as Putin
10) AHC: Female Soviet leader