Since you are mentioning 3DXchange5, I assume you have iClone 5, because that is what you would use. In iClone 5 you have the face-fitting tool and a drawing of a face with enough realism would work as will as a photo. As was a photo, it is important to have even lighting (no heavy shadows) for both sides of the face. You also have the option to include a side view for additional detail.
For iClone 6, this has become more complicated. It works the same for iClone 5 (G5) characters with a face-fitting tool inside iClone 6. However, for Character Creator characters you need to create a 3D face in CrazyTalk 8 Pipeline and then export it.
As to your other question, you can try to replace the body textures of the character with drawn images, but you cannot create a body shape based on drawings directly (at least not with RL products).