Can't we make it so that zombies can be killed by turrets in the safe zone? as well as by player turrets?

Player turrets will kill them.  If you have your turrets set to Peace Keeper mode the zombies have to attack you first.  If you set the turrets to attack all mode they will attack them regardless.

Merged post

Unless you mean an option to always attack them regardless of the mode that would be great actually...since the safe zone turrets do that.

If youre using TruePVE you can edit the config so add scarecrow to the npc class and add "guards can hurt npcs"