Interesting details provided here. I do wonder however was there any particular reason why life and death magic doesn't opperate like the other types of magic? Having life and death shards could have been very interesting for game-play and magic.
I have similar concerns, mostly because I had expected (hoped for) an alignment system that overlaid some sort of 'integrated metaphysics.' Prior to Brad's recent posts that make life and death magic seem mutually exclusive for any given sovereign, I'd imagined that Life was one of five elements, and whether you pursued magic like raising zombie slaves or healing wounded soldiers was a matter of ethical alignment. This OP leaves me seriously wondering why there are only five 'element' runes in the forum graphics background. If Life and Death are mutually exclusive, why aren't they represented by distinct runes?
I like no shard for life/death. If mana points depend completely of possesing shards, that means that no matter what you will always be able to use at least one type of magic.
Despite my fretting about life 'versus' death details, I really like the idea of individual channelers (sovereigns and appropriately imbued champions) being the mana sources for 'the Life element.' That sort of structure could support an Elemental analog to the Sorcery books in MoM, enabling all sovereigns to have access to some core common spells for communication, protection, and perhaps even countermagic.