but how could this stop the initial creation of immediate winners and losers from the first injection of new global currency by server admins?
It doesn't, but it does keep that from being a problem, since there will be more currency to go around, so those early winners will need to keep selling goods that people want to maintain their advantage.
With barter and minted currencies distributed through a player store perhaps at least those who pursued advanced tech could only get as many resources as people could collect themselves
The problem is not the free money. The problem is not enough money. You still end up with the tech players having all the money regardless of how the money is distributed.
Government stores buying goods to distribute money works OK, but has its own problems. Usually what happens is one or two goods are overpriced, someone notices this, and exploits it to make all...