The decision to award or not award a Fate Point is determined by a simple question, "does the aspect complicate the character's life?" If yes, then Fate Point. If no, then no Fate Point. Everything else is just decoration. If a skilled psychomancer has access to a captured NPC and has to decide between rifling through his thoughts the easy way or interrogating him the hard way, then the mage gets a Fate Point for choosing the hard way or the Lawbreaker power for choosing the easy way.
When it comes to killing NPCs with magic, remember that even mooks have the full suite of consequences (mild, minor, severe, and extreme). The practice of letting mooks Concede after taking only a mild consequence is a narrative device to separate the weak from the strong and keep the game moving at a brisk pace. So, if a wizard hits one of Nico's tongueless minions with a gout of flame, then consequences are applied as normal, up to and including an extreme consequence. If even the extreme won't save the brute, then it is perfectly reasonable that death is the only acceptable result of such an attack and the wizard breaks the First Law. If the brute can take enough consequences to avoid a Taken Out result and then follows it up with a Concession, then the wizard did not kill with magic and does not earn Lawbreaker. They may be crippled, maimed or just severely burned, and they may yet die from an infection or other complication, but such a death would not be directly caused by magic insofar as the Lawbreaker power is concerned (the White Council may see things differently, ahem).
So long as everyone at the table knows this at the start, then there's an objective line between killed and not-killed that doesn't require house rules or GM adjudication. It also serves as a nice line between murder and assault in regards to mortal law, too.
