How do I get RawTherapee to do absolutely nothing?

You can read about the neutral profile here: Sidecar Files - Processing Profiles - RawPedia

You’ll need white balance in order to demoasic your raw file, so turning it off isn’t a great idea.

There is also a film negative tool, for working with film negatives scanned with a DSLR: Any interest in a "film negative" feature in RT ?