Okay, here's an update. We irrigated Rockette's wounds again and only saw one maggot that we removed. The wounds look surprisingly better today. After irrigating them we sprayed them with Vetericyn Plus and we got Screw Worm Ear Tick Aerosol to help control the flies. Rockette is still separated from the others. She was much perkier after the treatment -- tail was up, she ate some meal worms and yogurt and even a little scrambled egg. And she was talking to me a bit.
Pearl's prolapse seems to have resolved itself for now. I gave her a bath and got her cute little [normally] fluffy butt cleaned up. One other chicken, Buffy, had some caked on poop and I got her cleaned as well. Everyone's really curious about what's going on but the others look fine as far as I can tell. As I said we're leaving town tomorrow morning so hopefully with a little attention from our house sitter all will be well, at least until we get back next weekend.
In answer to the question of what we feed the chickens: they have Purina Layena Layer Crumbles (16% protein) with Oyster Shell available at all times. They have grit and additional oyster shell available always. They free range for anywhere from 1/2 hour to 4-5 hours a day, though most of that time they like taking dust baths under my roses.
I lure them back into the coup at the end of the day with somewhere between a 1/3-1/2 cup of scratch (9 chickens) and 1/4-1/3 cup meal worms. [Hubby sometimes sneaks them more if he's trying to get them out of the way of where he's working -- I've tried to tell me not to, but...

] They have fresh water always available and today I went back to adding 1T/gallon apple cider vinegar to it.
We hadn't yet this season had any issues with flies but given the maggots we saw and the flies buzzing around all of a sudden, hubby yesterday put up the fly attractor bottle. It's doing it's job nicely.
And that's where we are -- no more time to do anything else right now unfortunately, but I welcome your thoughts/comments.