If the roost is against the wall, how are the chickens going to roost on it? It should be a minimum of 12" from a parallel wall for large fowl.
See? There is always a reasonable explanation

I figured you were holding them up to your face and took the hits.
In my opinion, if a chicken is too "assertive" with humans, it is aggression, not "Hi BFF!". I have one Ancona I'm not real sure about. If I squat down to do something she sometimes gets up on my shoulder. When I stand or brush her off she does the "I'm a pancake" squat so I know that SHE knows that I am higher in the pecking order. But lots of my chickens haven't yet figured out that freckles are not food, nor are small holes in hats, etc so I'm not about to let one sit on my shoulder and "hunt" for "food" on my face

It is bad enough in the summer when they think those dark things on my arm might be food. Of course, if I had a tick, they would be most welcome to them. Fortunately, I have never had a tick.
Yep, that will do it for most chickens. Some of mine are still not real sure about hand feeding but they are right there to get some if I throw it for them. Want to watch something funny? Throw some treats to one side of the chickens, then throw some the other way and watch the scramble. "A bird in the hand is worth two in the bush" is not a concept chickens seem to understand
It is not at all unusual for them to be nervous about new things. Just leave the lid open and the more adventurous will come out. The others will follow.
- Make sure you coat that chipboard really well with blackjack or some other sealer
- I don't understand the 3" gap. Once you have any sort of litter in there, it will be covered and do nothing. Better to have hardware covered gaps low in the walls high enough to be above the litter.