I kept a CX (cornish Cross) hen for almost 3 years. They do lay HUGE eggs, usually double yolkers. If you raise them and treat them like a normal chicken, they do pretty well. LilX would roost at night, foraged for bugs and was part of my mixed flock. And I did hatch several of her chicks! I had to be selective to be sure I didn't set the double yolked eggs. This last spring, she prolapsed. I did treat her but she didn't recover.
Yes, thats very true. If drakes are around chicken hens, and raised up with them, they will mate and kill the hens, different "plumbing". My scovy drakes are too big to catch a chicken hen and really don't seem interested. I had a mixed breed black drake, mallard derived, that did get one of my hens, made the mistake of raising him up with chicks. He went to the freezer. Any human aggressive rooster here, or any species aggressive male, goes. There are so many nice roos out there, and usually free its not worth the injuries and risk. One thing I have learned too, If you have multiple roos in your flock, and plenty of hens, roosters just don't get human aggressive. they are too busy being a rooster! I also handle them a LOT as chicks, and randomly grab up my adult fellas every day. I have a large mixed flock (currently well over 100 birds), several species of birds from geese to quail. The only species that don't free range or comingle are my quail.