I would hold back on the darks until you've filled your page. You can always make an area darker later, when you can relate it to other parts of the image. Making your darks lighters is a bit more difficult.
I would do some thumbnails of how you want the final image to be composed, and how you want your values distributed. You have a very specific environment in mind, so I would focus on readability. Your surrealist tendencies will no doubt show up even then, so I wouldn't worry about the image losing that quality.
Here's a paintover as an example of how you might plan out your values. Simplify. Try breaking things down into 4 values. Do this to your current image, and you'll see that things are pretty jumbled.
Also, here's a work by Hisaharu Motoda, as inspiration and reference.