There is no binary concept of omnipotence or total absence of power. There is a reality of constant empowerment and patient achievement of ever-higher results.
What is the purpose of doing chakra mantra like Complete Chakra Meditaiton, (Traditional, Runic, Sanskrit, Necronomicon, or Plantary)?
Each chakra controls an aspect of your being, to stop nourishing it is like to stop taking care of yourself and your existence. In addition, the chakras are fundamental parts of the soul, which is why if they stop being empowered, the soul stops developing in power. People who do not work on the chakras regularly do not gain power, and moreover they atrophy spiritually. It is a question of energetic empowerment.
Do we work on other parts of our soul like 3rd eye and clairvoyance/audience to see, hear to peer into the astral?
Specific power centers govern specific abilities. There are things, stages, that to reach them you have to work on what governs this type of power.
Our ultimate goal is to awaken our Kundalini energy and ascend it through the seven major chakras, ultimately achieving the Magnum Opus to become a God of our own. Yet, even after this transformation, there remains further evolution for us to embark upon.
The Magnum Opus, its highest achievement, is the Divine Condition, but once the divine condition is obtained, one does not stop empowering oneself. Even the Gods meditate to empower themselves more and more. Furthermore, if you want to obtain the Magnum Opus, going through spiritual empowerment is necessary.