What seems to me to be blatantly proto-existentialist is Kierkegaard's overarching conception of identity. According to the situation the aesthetic hero has been placed in there is a choice that is presented: to either disclose painful information or keep that information hidden and carry the burden of silence. When presented with this kind of dilemma the aesthetic hero must rely on only herself in order to make the decision. Additionally, the aesthetic hero's decision defines not only her relationship to other people,as a carrier of a hidden information or as the barer of bad news, but also the aesthetic hero's relationship to herself. The aesthetic hero stakes her identity in the decision that must be made.
The implication is that the aesthetic hero, like the knight of faith or the tragic hero, didn't really have a say in the dillema presented before her. For Kierkegaard there is a call to action that is beyond the capacities of the hero and that call requires a response, a decision. In the case of the aesthetic hero, I wonder which decision would be more true. For Hegel, it seems that te disclosing of information such that it is availible broadly in the ethical realm would be the way towards truth. It seems tat he might say that the decision to continue to keep the information hidden would be a step away from truth. Furthermore, Hegel may say that there is no decision to be made, as one has a responsibility to truth. But I am more inclined to say that Kierkegaard is implying that either way, whatever decision the aesthetic hero makes, the act of choosing contains the truth.
The situation of the aesthetic hero is a mundane one. More likely than not, everyone has been in a variation of the dillema described in Kierkegaards Fear and Trembling. Because of how average the scenario is, I am inclined think that it hints at Kierkegaards conception of free will as a contextualized series of decisions in which the individual must rely on herself for the answers. As mundane as it may be, the frequency at which the scenario occurs makes it seem that much more true to me.