I don't normally kill of my characters either, specially the immortal ones. So nothing to be ashamed of! ^.^ The ideas you have are very helpful! There are several that would work just fine though a stake through the heart would be the least painful to recover from.

For werewolves, they trigger others change from venom that is in every bite. However, the other has to die in order for the venom to take affect. As for how Devin changes other vampires, I do not know.