For both modes. Sadly there's not enough customization to be able to do what you want, you either enable death (and birth) for everyone or not.
That said, the risk of your own character being killed is pretty low, I think you can only die of old age and not from combat though I'm not 100% sure. However your companions and family can die in combat (and from old age), though it's also not extremely common and you can always reload a save if that happens.
NPC lords never execute anyone ever.