Right Hand Left Hand

Finished reading Right Hand Left Hand.  It is a great book to read if interested in the functional difference of the left and right side in ourselves.

Things I took away.

1. Asymmetry is important and probably beneficial.
2. The cause is probably genetic
3. There is a functional component that impacts the genetic origins.  

Things not addressed or are still unresolved in my mind.

1. Does not mention the ability to differentiate in movement the left and right side,or the dominant side has the ability in the axial skeleton to initiate movement in both sides.
2. Often mentions the pseudoneglect of the right visual field but does not go into if two people are interacting (in the frontal plane) they are neglecting the left half of face of each other and concentrating on each other's right half of face(left visual field).
3. If the right cerebral hemisphere can take over the speech center with an injury to the speech centers in the left cerebral hemisphere at an early age then what is the mechanism? and or can it be activated at a later age?
4. Can it be activated without an injury to the left speech centers?