OK....we've established that I am no expert so just understand that I'm raising these questions as part of my own learning process. 1. I see the roost is 65 inches in length? And you are getting 8 LF. If I remember right, the recommended roost space is "minimum" of 12" per bird.....so I was planning on 18" to give everyone enough space. If there's not enough you can end up with feather pulling and general crankiness. So....could you add another roost? Or even a tree branch or two so they have options?
Second thing......is there only one nesting box? Chickens are funny....they either "like" the nesting box or they go find their own place to lay. You may wish to provide some other choices for them that are acceptable to you so that they don't just lay them on the floor. I've seen folks use 5 gal buckets or plastic dish pans from the dollar store. I even saw a person that used cardboard boxes and threw them out weekly....that way they could move them around and find "the spot" that the hens liked before putting something more permanent.
None of this is meant as criticism.....because let's face it .....what do I know??

Just wanted to have conversation about these things....