Is the somatic system for voluntary movements?

Answer 1

Yes.
The somatic nervous system is the part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles, and with reception of external stimuli, which helps keep the body in touch with its surroundings (e.g., touch, hearing, and sight).

The system includes all the neurons connected with muscles, skin and sense organs. The somatic nervous system consists of afferent nerves that receive sensory information from external sources, and efferent nerves responsible for muscle contraction.

Answer 2

If you're talking efferents (fibers running away from the CNS) then yes. Neuroscientists refer to those as General Somatic Efferents. There are two types of afferents (those running to the CNS) called Special Somatic Afferents and General Somatic Afferents. The afferents are not used for voluntary movements but rather sensation. SSA pretty much come from your ear for hearing (CN VIII) and GSA comes from pretty much everything else (I'm definitely generalizing here). Pinch yourself on the arm or face, that's GSA.