ok so these are a few scenarios that you can make with world edit

scenario 1 wasteland

-go to custumized world and go to biome

-scroll till you find desert

-leave menu and create world

-take away villages for hardcore expirance

scenario 2 water world

-go to custumized world and rase water level to 80

-you make want to go creative to find a mountan (island) to start on

-for hardcore put it to 90 or 100


scenario 3 {sandscape}

basically the same as waste land but tune up dungeon and lake rarity

(note the fact that this is what i used for my past the northern dunes map)