I've read that deleting gravestones in Sims 2 ends up corrupting the game files, though I don't know if that applies to Sims 3. The graveyard in question is the one in Sunset Valley. I intend to replace it with Grim's Ghastly Manor, but I wanted to be sure it wouldn't have any negative effects.
@Hyerlobos If you're starting a new save, it should be fine. There might be issues if this is an existing save and the graveyard contains the graves or ghosts of sims that already died, but there are ways around that too.
In any case, it's a good idea to have NRaas ErrorTrap and Overwatch in place to clean up any stray data left behind when you delete the graveyard. And be sure to keep a backup copy of your save, because even when things are supposed to work out perfectly, something occasionally goes wrong. But in this case, that would be the exception rather than the rule.
