I'm sorry for "reviving" this thread, but I just discovered something that I did not find posted and that may be useful.
With Ambitions and World Adventures it is possible to populate graveyards without killing Sims! You have to join the Ghost Hunter career and collect spirits. Once you have 8 spirits of the same type/color, place them in the Carter's Display Case (the expensive one) and then transfigurate. It will spawn an urn. The urn's ghost will be elder and his/her traits are determined by the type of ghost, for example: Angry spirits can become Mean Spirited, Evil, Grumpy ghosts while Kind spirits can become Good, Family-Oriented, Friendly ghosts. Lost and Scared spirits can become Neurotic and Light Sleepers. You can easily move the urn to the graveyard.