As Aristotle might remind us, “power” is said in many ways. Each of these is different.
There is the power that Plato suggests as a distinguishing mark of being in the Sophist. There is the greater power he attributes to the Good more ancient than being. There is Aristotelian potentiality, which I normally prefer to distinguish from “power” altogether, but is referred to by the same Greek word. There is the related notion of power as capacity, of the sort developed by Paul Ricoeur. There is efficient causality, itself said in many ways. There is physical force. There is legal or political authority. There are repressive apparatuses. There is the positive, distributed social power involved in the formation of selves, discussed by Michel Foucault. There is the artistic and inventive power with which Nietzsche was especially concerned. There are claims of supernatural power beyond possible human understanding.
I haven’t yet found where in her French text Gwenaëlle Aubry clarifies how her identification of Aristotle’s god with pure act — involving neither Aristotelian potentiality nor Platonic power — goes together with her identification of the efficacy of the pure act with a final causality realized through “potentiality as tendency toward the end”. I think this has to do with the pure act’s role as an end or attractor, so that the potentiality in question belongs to the things it attracts, rather than to Aristotle’s god. Aristotle’s god for Aubry is what might be called an “inspiring” or attracting cause rather than a ruler and a driving cause.
It seems to me that in order to even be intelligible, a power of any kind must be understood as having definite characteristics related to its efficacy. I therefore think “infinite power” is devoid of sense. Even the “omnipotent” God of Leibniz who selects the best of all possible worlds at the moment of creation only selects an inherent, coherently realizable possibility that is also in accordance with non-arbitrary criteria of goodness. He does not create arbitrarily.