Slime mold is a super interesting system with effective complexity. Being organic, slime mold is pretty close to being right in the middle of total order and randomness, but due to it's behavior it leans more towards order. Slime mold works by first reaching out and finding food, then by forming efficient paths to the food, creating amazing synthesized systems to get to and from resources.
I really don't think that with generative art there is a "problem of authorship." I think the "artists hand" is an interesting notion that was questioned by people like Duchamp and Pollock and I think that generative art is another way of experimenting with that concept. Its also interesting to think about separation between arts and crafts, what turns a painter into an artist or a painting into art? well what turns computer code into art? Intention? The audience? The art-world? I think that these are important concepts to ponder and generative artists explore them, but through their artwork.