I know in Sims 2 you can't without corrupting the game save, and in Sims 4 you can delete any sim in the game. But I can't recall if it is safe to delete the premade sims in Sims 3. Is it safe to de...
It's not safe to delete them, but you can annihilate them with NRaas Master Controller. That will remove the sim, and their data that is programmed into the world.