Seeing as anything that we copy or make backups of now is not self-aware, I don’t see what that has to do with anything. If anything, a teleport (as conceived of and described in science fiction, not how it might “actually” work) is more like moving a file from one tree to another.

Sorry, no it's not. When you introduce technobabble related to "buffers" and "caches" where the information is stored temporarily, the working must conform to the way files are handled. Yes, you can handwave whatever you like for narrative purposes, but this discussion is not supposed to have as a valid answer "a wizard did it".

In order for me to be convinced that the common depiction of teleportation is a form of cloning and murder, I would need someone to prove to me that humans have souls in a metaphysical sense

That is ridiculous. Please search the short stories "The phantom of Kansas" by John Varley and "Think like a dinosaur" by James Patrick Kelly to see the implications of this kind of transport. Neither posits the existence of a soul, and the scenario of "the original dies, a copy keeps living" is very clearly shown as the only valid explanation, and how the assumption that the person is the same after the transport (or the cloning, in the first story, but the effect are the same) is merely a legal fiction for convenience.

In any transport there's a copy, and any copy takes a non-zero time and an instant where the copied person must exist in two places at the time. Unless the spacetime is curved and poked and you transit through the hole, there is no other viable model.