You are actually claiming science is based on assumption? If "science" approaches a subject with predefined or assumed knowledge, it is no longer "science" – it is the search for evidence to support your predetermined assumptions. If “science” starts with the position “we know it has nothing to do with god or a creator” – then it is no longer science – it is now dogma.
Scients are also human and have beliefs and conjectures that are outside science.
Of course. But science is a discipline, not a type of human being. What you are saying is like claiming football players do not always follow the rules of football (which is true) but that does not mean the rules are no longer necessary or important to the game.
If you think otherwise, perhaps you'd like to tell us about an experiment, even a thought experiment, that would demonstrate a supernatural event.
With all due respects, that statement does reveals a bit of ignorance on this subject. The realm of science is the natural world therefore science can never demonstrate a supernatural event (because if science can, it is no longer supernatural). Supernatural is an ever-changing state. Electricity was once supernatural because science could not explain it. Now science can explain it and it is no longer supernatural. In the future it is possible God will be part of our natural world (the world explainable by science)