An update on my girls.... but first, I'd like to thank all of you who have joined this thread with helpful suggestions and advice. This is a great forum and I am grateful to all who run it and who keep it available to us.
To recap: I kept Bossy in a small cage with straw in it (changed daily), food and water, so that she could move around her cage, not far, but had enough room to circle around, climb into her food and water bowls (lol), build a little nest to lay me an egg everyday, and to sleep at night, and I placed the cage where she could see the rest of the flock, and them her.
After a few days, it was suggested to me to move Bossy out of eyesight of the other birds completely, as, changing up the pecking order and "reintroducing" her to the flock at the end of her "time out", was key in getting her (hopefully) to stop being so overly aggressive towards 3 of her flock mates. So, I moved her away from the other birds for an additional 6 days where she was protected and out of sight.
This "experiment" has been VERY successful so far! Bossy is actually becoming more of a team player. She chills out with the rest of the flock during the day, instead of running roughshod over the other girls and her previously aggressive behaviors are not evident...fingers crossed. She even forages alone sometimes, instead of chasing after my little EE, Baby, who is also my little huntress, stealing all of the treats she would find and, in general, brow beating her.
Always before, Bossy seemed to want to stir up trouble by continually chasing the other birds, and by just being a busy body, poking her beak into everyone elses scratched areas, stealing any worms, geckos or snails they might come across (especially Baby's). As, I am sure you all have seen, if one hen finds a treasure, most of the other in the flock will try their darndest to take it from her, and the antics can get pretty humorous. Bossy has now joined in on the FUN, rather than aggressively pecking the other birds, even after the found treat has been consumed.
The most fortunate thing which has come from separating Bossy from the rest of the flock for the past week or more, besides the fact that the flock seems so much happier and content, is that my little EE's, Baby and Goldie, and my PBR, Braveheart, aren't cowed and terrorized by Bossy anymore, and they stand up for themselves, happily stealing treasures from her without acting scared. They also protect they're nest box when they are sitting on it and Bossy wants the same one. Whereas before, if Bossy wanted that box, she'd peck their faces to the point of drawing blood, or climb in on top of them, until they gave it up. She might make some noise now, voicing her displeasure when "HER" box is occupied, but she knows better than to go all Rambo on the other hens it seems.
After allowing Bossy to hang with her flock mates, I continued to cage Bossy at night, for several nights, so she didn't pick up her old bad habit of biting feet and faces, drawing blood, while on the roost. As of last night, she is roosting with the rest of the flock, cuddling up to my other RIR, Kea, who has taken the top spot in the pecking order.
I haven't noticed any more feather eating on Bossy's part either, and, per all of your suggestions, I am cutting out all treats, except tuna, hard boiled eggs and mealworms, from the flocks diet. The 6 girls continue to give me 5-6 eggs everyday, and I get many compliments on their appearance and taste so that's good.
Again, mahalo all for your kind advice. If you would like, I will update this thread in a week or two to let you know how it's going. Aloha