Your red super ball and my red super ball analogize to the 2 consistent depictions of Luke Skywalker. Both red super balls (Luke Skywalker) share a certain set of traits that we recognize as similar. That's how we (the authors) can write about Luke Skywalker in a consistent way even though Luke Skywalker is just an arrangement of ink on a page, because we've identified what specific arrangement of ink people identify as Luke.
To get back to the point, I think that in order for something to have free will, it has to be an animate object. Nobody asks if a rock has free will because the very idea is ludicrous. Similarly, ink on a page as no free will.
But those traits aren't a part of the ink on the page... they exist n the mind of the reader and their existence in the collective consciousness of all the readers grants existence to the character independent of the writer... I feel like we're going around in circles here...
The traits themselves may exist in the minds of the reader, but their association with the character is only because of the ink.
For example, let's say we think that one of Bob's character traits is that he's brave. Here's how we came to that conclusion:
Chapter 1 - Bob does something brave.
Chapter 2 - Bob does something brave.
Chapter 3 - Bob does something brave.
Etc.
The author has conveyed the idea that the character of Bob is brave through repeated examples. However if instead the author had written:
Chapter 1 - Bob does something cowardly.
Chapter 2 - Bob does something cowardly.
Chapter 3 - Bob does something cowardly.
Etc.
We would no longer think Bob is brave, we would think he was cowardly instead. The way we think of the character is entirely defined by the words chosen by the author.
For a better analogy than the super ball, the character can be thought of as a puppet. A puppet might look like it exists as an independent entity, but in reality everything it does is decided entirely by the puppet master. The puppet offers zero input into the decisions because it is nothing more than a specific arrangement of cloth and is therefore incapable of offering input.