Rapping is very good for health because you exercise the body  while doing so and the messages are sometimes very deep
What exercises do you do while rapping, that may enhance vocal delivery or rhythmic speech?
I can't tell for sure but I know,  it involves breath control and the movement of the windpipe and this can be good for health
What other stylistic elements do you do while rapping?
Sometimes you have to dance to the rhythm of what you are rapping to. So you move your body and your hands accordingly 
Any songs you like to sample or use bass lines from while you rap?
I consider Tupac as the greatest rapper of all time. His songs are deep and never go out of style
Yes, can't believe Tupac ied so young in 1996