I am in agreement that you *probably* don't need to use Corid. Though it may not hurt them either. I will say that Corid works by blocking thiamine and starving out the coccidia that are in EVERY single chicken poo. So Nutri drench actually doesn't have the B's which I think are vital to energy and recovery from things, but it may still be effective if using Corid.. since you should NOT supplement vitamins (specifically the B's) because that would defeat the purpose. I personally prefer to use another bird vitamin with B's in it, but do also have the nutridrench as it was so touted by people.
As far as your chooks having damaged lungs and such, the body is an amazing, self healing, living organism. So IF they do have lung damage, they will probably fully recover from it.
So happy to her that some of your community are pulling together to help, to the best of their ability!
I know you challenge is not over even if you aren't fearing for you life anymore. I hope you will continue to get support and that your animals pull through as well. Keep holding on, there's a light at the end of the tunnel!
I don't know... what I wouldn't give to see a pic of you and your kids right now?!