I had read in an animation article long ago that it is important to add effort in humanizing the eyes and hand animation because thats where people look at.

Lets focus on the hands for now.

Importing a bvh humanized V4's movements but the hands and fingers stay stiff. Though I could apply hand poses, the results can be dissatisfying or the process time consuming.

Is there a way to naturalize the hands and fingers with subtle grasping like how a real person uses his hand gestures when in a coversation? 

Passion is anger and love combined. So if it looks angry, give it some love!