I just realized the drawback to submitting a script to a movie company. I can draw, and I want to have a say in the art direction. I also want to direct and produce. In summary, I wouldn't be happy with anything a producer made with my stuff because I want to have control over the product. When making my own novel, or comic or animation, I have that control.
My first attempt at directing was pretty bad because I was too democratic. I'm not sure I want to be a dictator, though. I thought about paying artists at art auctions for their services, but that's a crap shoot. I can't tell which one is a good artist, and some overinflate their prices. But it's important for me to recognize that I shouldn't try submitting scripts to places because of this. In fact, submitting a novel is a bad idea because the whole point is to get someone to film it.