I enjoyed the intro of how you educated yourself about chickens and their needs.
The brooder is fantastic and having it in two halves means a larger group of chicks can be separated for easier management, or you could even have two age groups at the same time.
I like some of the details in this coop, like the combo pop door/cleaning access door and the under roost poop catching box. Really, really wish this article came with larger photos as I would love to see that in more detail!
I assume the brooder lamp inside the coop is for heat in the winter? I would urge caution in using it as a regular fixture as it is a fire hazard. Would love to see more details about ventilation since I can only see the one window, hopefully there's some directly under the roof line as a lack of ventilation could really amp up humidity inside the coop during winter, which can lead to frostbite (assuming the coop is located in a climate where cold is an issue). Not sure about the practicality of outside egg boxes but I am curious if hens would actually use them, and if weather would make it a bad idea?