Those were all great ideas! We are going to build a new coop and I'm integrating a brooder! I've used a separate coop and run for that, but I love the idea of everyone going into the same space at night. It will be a 2020 project, but we are busy planning it now, gathering all the ideas we can.
We have visited the coop design forum many times. Thanks for sharing your brooder design and process! 
Yes, we went ahead and let them out. Mama hen has been really good, very protective. Clucking at her chicks while pecking the **** out of anything that gets near. I think they will be ok.
I recently read a post on here about how a large herd dog will protect chickens if it has been allowed to grow up with them. I don't remember exactly what the name was, but you might be on to something. In the case of the poster, they used to have trouble with predators and that stopped with their large herd dog. (I just know I don't have that term right) I know a great Pyrenees is large, so I'm hoping that will do the trick for you.
Yup, broody Mama's are fierce!
The dog is cool with tiny chicks?
Yes, they are great. Actually they are the key to our whole operation. They are a little over 19 months old and have been with the chickens since they were 2 months old. We can put chickens on top of them and they don’t even get excited, usually they don’t even watch them when we do that. We have not lost a single chicken to them and when they have been on duty we have not lost a single chicken to predators. We have coyotes, foxes, raccoons, and hawks for sure and I wouldn’t be surprised if we have others I don’t know. They keep them all away.
well, that is just awesome.
