#Regarding Getting the Right Maps to Load
also in defaultengine.ini, you could set the map this way, I observed this from 3rd person code starter project, the names are slightly different now:
[/Script/EngineSettings.GameMapsSettings]
GameDefaultMap=/Game/Maps/Victory
ServerStartupMap=/Game/Maps/Victory
EditorStartupMap=/Game/Maps/Victory
#Regarding Getting the Right Game Type to Load
In DefaultGame.ini
[/Script/Engine.WorldInfo] ;beta4
GlobalDefaultGameType="/Script/VictoryGame.VictoryGameGameInfo"
becomes
[/Script/Engine.WorldSettings]
GlobalDefaultGameMode="/Script/VictoryGame.VictoryGameGameInfo"
GlobalDefaultServerGameMode="/Script/VictoryGame.VictoryGameGameInfo"
please note VictoryGameGameInfo is my AGameMode extending class