Welcome to BYC.
Concerning the letter:
First, chicken coops, in general are not filthy. That depends on the caretaker, the design, and they space allowed per chicken. The more space, the less mess to clean up.
Second rodents and roaches are not inevitable. They shouldn't be a problem is the area is kept clean.
Predators may increase.
Coops and runs need to have security requirements.
This will protect the chickens and encourage the predators to move on.
Noise can be an issue. Hens who are laying are quite loud. There is just no rebuttal to this one. It can be somewhat minimized by having a no rooster rule.
You can research coops & runs and security. Present your idea of requirements to keep out predators and keep a clean area.
Also, I'd like to point out, that while I love chickens, they are not glamorous. Chicken keeping is not glamorous. Unfortunately, a lot people go into it because some youtube videos have made it trendy. For the sake of the chickens, educate yourself well before you decide they are for you.
Good luck!