Is he who denies God's attributes and metaphorically interprets them—such as interpreting "God's hand" as God's power—considered to have departed from the fold of Islam, or is he merely not among the people of the Sunnah?

Ahl al-Sunnah (definition) wa al-Jama'ah believe in the Names and Attributes mentioned in the Quran and Sunnah without ta'wil (figurative interpretation), tamthil (likening Allah to creation), tahrif (distortion), or ta'til (negation). They consider anyone who denies Allah's Names or Attributes entirely to be a disbeliever. And whoever denies a Name or Attribute established in the Book of Allah is a disbeliever because he is belying the Quran. As for those who ta'awwal (interpret figuratively) some Attributes and distort them from their apparent meaning, such as the Ash'aris, they are innovators and mistaken, but they are not disbelievers. They may be excused due to their ijtihad (definition) (independent reasoning) and ta'wil.