Awww I hope you find a home for her. Good job with all you have done to help her out!
I am sure she is feeling much better for all your wonderful care.
Feather plucking can be from lice/mites as well as stress/boredom, or protein deficiency.
I am not sure why she is making noises at night. My hens are quiet at night. Yes they do get INCREDIBLY lonely. They are herd animals. (Well, flock animals.)
I once read a study where they fed chickens all white rice and they died from malnutrition. When fed brown rice they lived in the short term.
White rice is only a treat. Brown rice has its nutrition intact.
Any single grain isn't really sufficient. And chickens cannot live on grains alone...