Necromancy doesn't necessarily have to be about killing and reanimating. It can also be about controlling ghosts and the likes. Maybe not even ghosts, just death energy of some kind or another.
You could look at it like this: every action has an equal but opposite reaction. So every spell you do is not one action, but a pair of action-reaction. Now most wizards learn to use magic a certain way, what I would call the action in the simile. Necromantic magic seems to work the other way around, creating what would usually be the reaction, so the action occurs. Granted, this will only translate very roughly to magic, but I hope you get my point. Necromancy, without killing or raising anyone or anything. Harry says so himself, Magic springs from life, Necromancy from death. Kumori says something along those lines as well, and she says that Necromancy can be turned to do good.
In some applications, the necromantic method might even be better than the magic everyone else is using. We don't have much to go on there, but I think that could be something that would let you walk the straight and narrow, while still having necromancy.
Spinning off this idea, every warden of the white council will probably feel the necromantic energies around you, that doesn't seem to be something that can easily be hidden. However. once they soulgaze you they will find out, that you never killed anyone, never intend to, that there is something about the necromantic energy around you, that might not be inherently bad, and they will definitely see, that you never broke a law. Add to that a sponsor, and you are good to go.
I would keep Kemmlerian Necromancy from your sheet, though, because that definitely is the darkest dark of necromancy and will, like Deadmanwalking said almost certainly come with a lawbreaker. attached. If you do put it on your sheet and use it, you will end up on the dark side, and if you don't use it, you have two points of dead weight in your refresh pool. Refinement would be the better way to go there, I think. If you want to have a Kemmlerian background, put it in one of your aspects, so if you really want to go there, you can draw upon it that way.
Speaking of aspects: I think "walking the line" and "if the ref doesn't see it, it's legal" are basically saying the same thing, and I feel that the second one is way more fuego than the first, and might make for a better trouble aspect, while conveying the same message.
