There is no axiom accepted by science that forbids scientific inquiry into origin questions.
In your zeal to declare science all-powerful, you neglect to account for an infinitesimal fact wedged between existence and "Truth".
You can prove that there are at least the two distinct areas of study which are applicable to the nature of existence, but you cannot prove that they will find ultimate answers which are "TRUE" for any and all 'geometries' or frames of reference, or whatever relativism might be invoked. That is the ultimate difference between science, as a means of learning, and faith as a means of determining "TRUTH". They intertwine in fascinating and unexpected ways, and often in uncomfortable and undesirable ways, but neither exists in a vacuum. For "SCIENCE" to be something of value you must eschew "TRUTH" and remain agnostic about validity of theories, and this is a seemingly transitive equality, to accept faith, one must eschew relativism in some domains.
The really interesting element for all of this is, how does this zero-sum-game between objectivism and absolutism affect the human condition?