On the overall point you make in your piece I agree, the pedagogy of disciplines should always be politely challenged. Without doing so there can be no growth. I also agree that, like with most specialized fields, there are many who abuse the subject’s “laws” as a way to feign intelligence. However there are a few specific examples that you use in your article that I do not believe fit with your overall point.
Firstly the line you draw between what you call “natural” and “social” sciences is inaccurate. As a materials engineer I can guarantee you that most studies and experiments begin with an assumption, we presuppose the truth and then seek to prove it using data and results. Economics, indeed many of what I think you would consider “social” sciences, are just the same. Economists start by assuming they know what the outcome of a testable event is and then an experiment is conducted. The results of that experiment then go on to prove or disprove the assumption. Finally, economic studies, on the whole, are repeatable, just as physics studies are. When the same or similar economic event arises another experiment is conducted and the body of evidence grows. As for the minimum wage consideration, we have experiments (Seattle and the like) going on all over the country right now, it is just unclear what the results are as of yet. Thus, making the claim that economic study merely seeks to create doctrine based on the idea that physics or chemistry do not presuppose the truth is unfounded.
Secondly, I disagree with your challenge of the Rational Choice Theory. Yes humans can be irrational, but no one studying economics denies that. However, I think on the whole, especially when money is concerned, humans tend to be more rational. For many, acting rationally with their money means the difference between good and hard times. There is real, living incentive for one to be carful about the economic and financial decisions they make. Rational Choice Theory is something that was developed to examine the economics of nations with many thousands of economic participants, thus I think it can be reliably assumed that the majority of those participants will act rationally. Further, I would argue that the converse makes economics impossible to formally study, by definition. If instead we assume that all humans act irrationally, then we cannot preform experiments. Every result would be circumstantial, everything would depend on each human and the specific way they acted irrationally. I think every serious economist uses the grain of wisdom inside the statement “humans act rationally” for what it is, a method of exchangeability. The real strength of Rational Choice Theory is that for any given person presented with a choice between a more valuable outcome and a less valuable outcome, the former will always be chosen. This gives economists a method of comparison between populations and between decisions.
As a final note, I believe that it is unfair to say that economic laws do not apply if one does not study every single situation. There is value to a body of evidence. If an economic law is found to work in many circumstances, using the law to predict an outcome is highly sensible. As you wrote economics has led to many advances, and I would claim that these advances would not have happened without the kind of formal understanding that led to concepts of “value” and “wealth” as well as laws from supply and demand to production before desire.