Maddoc sat amid a pile of unrecognizable corpses. Men, Dwarves, Orcs, you couldn't tell. He periodically took a stab at one with his new knife and screamed, "STOP LAUGHING AT ME!"
I am the mask that grins and lies
I'll hide your face and shield your eyes....
A possible answer to what happens to spells when a mage dies. If the spell is strong enough, say and enchantment or other permenant effect, part of the mages spirit may become lodged in the magic. It may be a way for items to gain some kind of intelligence, but a mage who has knowledge of this fact would be very hesitant about enchanting anyone or thing. He might have other plans for his afterlife than counting the change in your bag of holding.
Preists, I think, would have this sort of thing covered.