The translators of the KJV did a good job for 1611, but it is not good enough for modern people. Too much science has occurred to think there were waters above waters and "firmaments".
We also know bats aren't birds and insects have six legs.
The Jussive tense is a third person imperative. Most of the passages you quoted are commands from God in this tense. "Let there be light" is a third person command. It means God said, "BE LIGHT!" and light "beed". ;-)
That's right...third person imperative....but when it came to Man...it becomes first person self directive!(the "us" being Father, son, spirit in collaborative communion)
The third person imperitive implies that God is commanding the material universe to produce what he wants thru its various processess, though not necessarily being totally involved at every step. Many Darwinists could be happy here though they would have to grudgingly admit that man was created outside of the matter energy matrix process that originally created the world and its simpler life forms
The first person self directive implies that God actually steps in and personally fashions matter into man directly from his hands! Christians and Jews could be happpy with this premise while giving ground to the evolutionists on the other aspects of living things.