2004-10-04 : If you have zero or negative life, half your life is zero, so it costs nothing to use the ability.

2004-10-04 : When it turns into a creature, it is no longer an enchantment.

2008-08-01 : A noncreature permanent that turns into a creature can attack, and its {T} abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.