I don't know if this is even relevant, but a lot of the time I talk of art as an autonomous object. I say things like "what the music is trying to do", "what this symphony is saying", etc. This is either totally irrelevant or maybe a difference in how much we concentrate on artists.
I think this just struck me as strange as it's just kind of a weird way to describe how the concept of artistic intent is usually used. We certainly can define it as the contents of the work itself but this just seems like bypassing the so-called intentional fallacy by defining the artist's intent as the contents of the art. I don't know if this is strictly wrong (someone who actually knows about art philosophy as more than a layman can chime in) but it seems a bit like trying to have it two ways at once.
I really appreciate these observations. Speaking of tthe artist's intent as it's embodied in the work really isn't a sleight of hand or a case of having it both ways. Works of art, as they progress under the artist's hand, do become more and more "autonomous." They increasingly take on a life of their own and dictate to the artist what choices are possible or preferable. The further along a work progresses, the more definite its character becomes, and the more specific and well-defined the options for continuation. Some possibilities will open up, while others will be eliminated. Novelists say that as they develop a story their characters begin to dictate to them, and something analogous happens in developing the structure of even the most abstract arts such as music. I observe it happen as I improvise at the piano, when what I've already done both generates ideas for what comes later and restricts my reasonable choices. If I make a choice that injects an element of surprise and doesn't seem "logical" at first, I look for a way to continue from there that makes the surprise feel right in retrospect and so gives the work a coherent character when taken as a whole. The creative process consists of constantly weighing one thing against another, looking both back at what's already been done and forward to what might come, with the intention of creating a definite conception that will impress the listener, viewer or reader as making sense.
Given the evolution of an art work in its creation, the "artist's intent" is seen not to be a static thing. Works often turn out to be quite different from what the artist imagined or planned at the start. The work increasingly dictates its own progress; the work becomes the master, and the artist its servant. This can make our search for the "artist's intent" a rather speculaive venture, and in some cases entirely unproductive. What we have is the evidence of the work itself, and the question, always somewhere in our subconscious as we listen, of whether what we're hearing at the moment makes sense and suggests a meaningful intention on the artist's part, regardless of whether tthat intention was the one the artist initially set out to realize. A listener to a piece of music is exercising, at the receiving end of an artistic transaction, the same faculty of aesthetic perception that the artist exercised at the creating end (though of course his job is much easier!), and he, like the artist, will judge whether, in the end, the work succeeds in doing "what it's trying to do."
So what was Beethoven's "intent" when he began work on his Fifth? Who knows? But he's an interesting case in that we have many discarded sketches showing some of the ideas he considered and rejected in the course of composition. Leonard Bernstein gave an interesting talk on the first movement of the Fifth in which he speculated on how Beethoven might have used some of the sketches; he inserted them in parts of the movement where they might fit and had the NY Philharmonic play the result, and then discussed how they compared with Beethoven's final choices. The lecture turned on some light bulbs for me when I first heard it as a young artist, helping me to understand what it was I was doing as both a maker and a receiver of art.
I'm not sure how well this addresses your points, but it's where my mind went in reaction to them.