Working on it! I'm having surgery tomorrow and will be in hospital for a couple of days, so I'm aiming for early next week!
Leylines are simply rivers of raw energy flowing beneath the surface. The are the source of power for users of arcane magic. Ley energy is also quite volatile and must be condensed somehow or contained.
I'll think about it. Shapeshifters have never occurred to me, so I'll get back to you. :)