Hello and welcome to BYC. Bless your heart for trying to help all these poor animals. It can be overwhelming sometimes how many that either need a home or medical care. I agree with dobie lover that you shouldn't count on guineas to protect against rats. Invest in some good quality rat traps.
I'm so glad you decided to join us here.
Enjoy those birds! I am so sorry for the chicks you lost. Bless your kind heart for rescuing! I was so relieved, reading your story that you were wise enough to isolate your rescue chicks! And very impressed at your chicken nursing skills. Know that the chicks that passed knew they were cared for, and were as comfortable as they could be, thanks to you. Best wishes with the remaining chicks!