They began by equalizing all things . . . . They knew that each thing had something acceptable and something unacceptable about it and declared, 'To make a choice is to lose the all-pervading; when one thing is taught, something else is blocked out. But the Dao excludes nothing.
(Zhuangzi 33; Ziporyn)
Though I may have already largely answered the questions with which I began this inquiry (Was Shenzi an "absolutist" who believed in a metaphysical Dao? [Yes.] If so, does this matter in terms of realizing positive outcomes? [Yes.]), there is still a lot to learn from continuing our inquiry. This is especially so since his philosophy seems so like that of Zhuangzi. Some of this apparent similarity may be a consequence of the author's having superimposed Zhuangzian terminology onto Shenzi. If we agree with Liu that this chapter is, despite all its divergences, representative of a school of Zhuangzi (Huang-Lao), then we can understand how he might have done so.
Yet another similarity is found in the quote above where we are told that "when one thing is taught, something else is blocked out". This echoes (or is echoed by) Zhuangzi in the Qiwulun chapter (2) in his discussion of "fullness" (cheng) in answer to his question of whether there is really any difference between waning and fullness. That Zhao Wen was rightly celebrated as a most accomplished zither player is agreed, but was this truly "completion" (cheng)? Not only is Zhao no more, but his son can only manage to manhandle the zither. Thus completion is such only by virtue of limiting our perspective. Ultimately, we must admit that completion is always relative to the degree to which we are willing to exclude a wider view. This corresponds to following a way, "something taught"; to follow a way is to exclude other ways. To choose one thing is to exclude others. Such is life.
Shenzi takes this as a call to abandon all choosing, to become inert like a clod of earth, and thus to follow no path at all (except this one!). Quite to the contrary, Zhuangzi takes it as an opportunity to fully engage in the requirements of our existential experience while simultaneously being informed of its tenuous nature. Choosing one way may of necessity be the negating of other ways in the matter of choice, but it need not be the negating of those other ways as a matter of validity. The affirmation of one thing need not entail the denial of anything else. This is part of the subtlety of Zhuangzi’s position. Never does he suggest we abandon the necessary individuation of our existence, but simply suggests that we need not attach to our choices as if to something fixed and “complete”. It is this flexibility that enables us to wander and to play.
You can check out Scott's writings on Zhuangzi here.