Why does God perform a 'Cesarean operation' on Adam so a rib can be born?

Figuratively speaking a rib is very important in a man"s life

It is an allegory so do not take it literally. It's like the "day of Creation" is not necessarily 24 hours long but can be understood as meaning eons of time, or millions of years, not hours.

The masses found it difficult to understand the inner teachings (esoteric) so it was easier to present them with an image in physical form which really represented a principle in Creation. This is a brief quote from "I Am the Life" by Murdo MacDonald-Bayne which describes this subject, as follows:

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The Father is the Consciousness--the will which directs. The Mother is the Intelligence--automatic in nature, and brings forms forth. The Substance is the womb or vehicle in which the Consciousness and Intelligence forms its own creation. This Substance is also called mind. In the record of the Creation of Man--in Genesis it says: "Adam was asleep. God took from him a rib, and made a mate, and called the mate 'Woman'." The significance of this is the similarity with the Infinite, who creates within Himself, a spouse, through which the manifestation of His creation would take place.

The Spouse is the Intelligence and Substance, through which all forms are created, which was created out of the Infinite by the Infinite, for there is no other possible source from which it could come. ...

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As with all of these creation stories there isn't a shred of truth in them. The human race are a result of evolution, not the creation of some mythical being.