Despite your derisive tone, yes, science does have presuppositions, e.g. the uniformity of natural law; and biases, e.g. a bias against ad hoc explanations.
The distinction between "natural" and "supernatural" therefore is hardly arbitrary if, by a "supernatural" agent, we mean (as most English speakers do) one that can supersede natural law at will or whim.
Now, science is simply a means of trying to understand the natural world. Its methods, presuppositions and biases have been determined by what experience and results teach about what works best in advancing this aim.
If you can demonstrate how a science without the presupposition of uniform natural law can actually work in advancing usable or perspicuous knowledge of the natural world, go ahead. Or encourage others more able to do so. Scientists will gladly, as they have at various times previously, abandon or modify their operational presuppositions in order to admit a genuinely useful theory or principle.
WARNING/HINT: "Genuinely useful" is the tricky part.
Science undertaken with the presupposition of natural law is science undertaken with the presuppostion of intelligent design. The fact that an intelligent agent may at any time override natural law is no more "supernatural" than the fact that the owner of a car can intervene, soup things up, tear things down, build them again, or make something up altogether different out of the very same raw materials.