Is it valid to make the adherence to a specific madhhab or the saying of a scholar conditional upon doing something, intending something, or saying something? And does that result in a breach of an oath, making the adherence binding upon the person, by analogy with making divorce and vows conditional?

It is permissible for a person to adopt a recognized opinion among the people of knowledge, and he is not obligated to adhere to a specific madhhab (school of thought). It is permissible to follow the four imams and others whose madhhab has been preserved, documented, and its conditions known. As for someone who conditioned his following (taqlid) upon a statement or intention, such as saying, "If I enter this house, I will have adopted a specific madhhab," and then he enters it, he is not considered to have broken an oath, and no expiation is required of him.