Get an automatic door. You will tell yourself I should have gotten this years ago. I replace the batteries in mine once a year and have never had an issue.
Atrium is going to be covered in chicken poop which will be tracked into the house. Chickens should be outside and enjoy watching them from the atrium.
The issue with the breed matters when it comes to sexing the chicks. Some breeds can be sexed based off characteristics some can’t. People here mostly want To give you accurate info but facts matter. Hopefully you got a good layer that brings you enjoyment that’s what’s important