But he DID have his body... we know that because he was in Namines little Flower thingy. not to mention that he Got his body back AFTER Roxas was created. Therefore, he doesn't have Sora's body. Thus the term NObody.
The term Nobody is meant to mean they are noone, nothing
Nobodies are made of the Body+Soul.
And yes, he was purified, up until the point he ran out on Donald and Goofy, which was pretty dark;P