The three parts of the title are interconnected topics.
The first part, referring to oral traditions, is all-important, since oral poetry shaped not only the Epic Cycle but also the Homeric Iliad and Odyssey. The formulation I have just offered is supported by the main line of argumentation I offer here. As we will see, I argue that the oral poetic traditions of the Cycle cannot be divorced from corresponding traditions that we find in the Iliad and Odyssey.
As for the second part of the title, referring to written texts, I must note from the start: there exists no proof for saying that the technology of alphabetic writing was needed for either the composition or the performance of the Homeric poems. Further, in the case of the Cycle, the textual evidence is simply too meager in comparison with the corresponding evidence of the Iliad and Odyssey; so, again, there exists no proof for saying that the composition of epics in the Cycle was somehow dependent on the technology of writing. Quite the contrary, it can be shown that these epics, like the Iliad and Odyssey, did in fact originate from oral traditions.
And now we come to the third part of the title, referring to questions of authorship. As we will see, such questions cannot be addressed in terms of written texts until we address them in terms of oral traditions. That is because, as I will argue, the attribution of authorship to obscure figures such as Arctinus of Miletus and Lesches of Mytilene or to even more obscure figures such as Thestorides of Phocaea can be understood only in terms of oral traditions. And such attributions of authorship, as I will also argue, depended on the idea that Homer was the author of only the Iliad and the Odyssey. That idea, which took final shape only at a relatively later stage in the history of ancient Greek epic traditions, brings us back full circle to what I have already announced as the main line of my argumentation: that the oral poetic traditions of the Epic Cycle cannot be divorced from corresponding traditions that we find in the Homeric Iliad and Odyssey.