Devils are LE, and work with lawyers frequently enough that they manage to buy their souls rather frequently. They had souls, they just have probably sold their soul. The lawyer one should be terrified of isn't the LE lawyer, it's the CG lawyer
In at least two campaigns I've been in, the wizards college's law department was always on fire and smelled of burning sulfur. Apparently they just like it that way?
Both times we ended up down there to summon an Arch devil so they could properly word a Wish for us.
Depends entirely on the limitations of the ghost's possession ability, but if the ghost can possess a living person and control them, then an animated corpse should work as well. The problem with continuing the career is that the body would continue to decay until the ghost wouldn't be able to move it any more.