FWIW, “You have to want someone dead, not necessarily the same person” is essentially how “intent to kill” works in a legal sense. That is, the distinction between murder and manslaughter is whether, by your actions, you intended to kill someone; under the law, it doesn’t matter whether the person actually killed was the person you intended to kill, or not.
Not that the rules of magic are necessarily modeled after modern US jurisprudence, but it might be that they both reflect a deeper moral concept.
I think so (it’s been quite a few years since my brief foray into law school). Let me do some quick Googling...
Yep, there it is: Looks like it may vary in different jurisdictions, but