Thank you for your response.
You are making the mistake the Dawkins make in taking an atomistic reductionist view of reality in his gene-centered view of evolution. I am sure that you know that volcanos are the result of way the earth was formed with a large iron molten core and a thin veneer of rock and soil. Without this core the earth would not exist and volcanos play an important role in the formation of the earth.
When taken in isolation one might wonder why we need volcanos, but taken together we see how they fit into the integrated whole that is our planet and our universe. The wonder is that all of these diverse elements (air, water, solid elements, hydrocarbons, time, space, light, etc.) work together to make a rational, intricate, improbably balanced reality.
On a slightly different tack it is very improbable that I will die on any particular day, but this does not mean that it is very improbable that I will die. In fact I know that the probability that I will die is 100% unsettling as this may be.
People are warned when a volcano is about to erupt and should know that rivers flood also.
The initial singularity and the Big Bang are not a natural event because they created time, space, and nature. It does not have a rational cause because it is beyond the physical and the rational. The only way we can say it is rational is because it developed into a rational universe. The same thing for God. We can affirm God is rational because God created a rational universe, not because we understand God.