I am sure your rooster will not mind his son hanging about. I have 6 roosters and they all get on fine. I think your blind one will not try to fight the older rooster as he won't be able to see him, so the older one will not see him as a threat. But, I hope he will be a she for you, as then you have no worries.
My chicken was like that since I bough her as a pullet from a pet shop with some other hens. I soon noticed something not quite right as her behaviour was strange. I would see her out of the coop happily walking about on her own after dark! She also had trouble picking up food or drinking - she always bobs her head up and down many times until she touches the food. She will dunk her entire head under the water to drink! I thought she was slightly brain damaged, but then I realised she was nearly blind.
Her eyes were not right - the black pupils were always wide open - even in bright daylight. She can see large moving things and will run to them - like my dog or the roosters tails. She likes to press herself next to my leg - even climbing on my foot in the run. So I have to be careful not to step back onto her.
It took her ages to use a roost. Now she will jump up and down like a spring until she 'hits' the roost - and they she will grab it!
I will never re - home her as I am sure she will die if someone does not make sure she gets enough to eat and drink. I have a problem with my own eyes, and so I share a special bond with her and she teaches me not keep trying until I can do something - she never gives up or gets depressed!
A very strange thing is that all the other hens are lovely to her! She seems to get away with the pecking order thing. They let her push through them into the food and land on them on the roost! I never seen another hen peck at her. Perhaps its because they know she never steals their treats!
Your chickens are so cute! I love the feathers on the legs. Here are a few pics of my gang. See if you can spot Perkin!