Good heavens your fast! Thank you.
You wrote: 6) How does the poop look? Normal? Bloody? Runny? etc. RUNNY, WATERY, BUBBLY;
Have you ever wormed these hens before? Are the droppings rather greenish?
If you haven't wormed within the last 4-6 months, I'd suspect worms. Frothy droppings could be a sign of it combined with the other symptoms.
However, there are also some foods that lately have been causing frothiness of droppings - but usually tan, not green.
The heat is also implicated in the whole issue. It's very hot, they might be drinking more. Have you seen one's droppings literally immediately after she pooped? Are they runny then? Sometimes when birds drink a lot in the water, the third portion of their droppings (the urine - clear portion that's like water) is excessive and it'll wet down their feces (the wormlike solid part) so that the entire dropping looks runny when you find it. Though it might not be quite as runny when dropped.
I find that a number of my birds also have runnier droppings in the summer. But not frothy. Frothy most commonly is worms (without being able to really know more about them.)
The drop in laying also can be from that and the heat. The droopy comb can be heat or anemia.
I'd pick them all up and make good and sure that there are no parasites as they're bad this time of year. (Check very very carefully all on their bodies, particularly their vents and backs of their necks for any moving objects or the egg clusters of parasites.) You want to rule out anemia from that which can also cause what you're describing. If you find bugs, let us know here in the same thread.
In the mean time, if you haven't wormed in a year, I'd pick up a bottle of Wazine 17 (piperazine 17% solution is the chemical name). You treat them one day in the water, don't eat eggs or meat for 14 days. It's meant to be retreated in 14 days or to be followed up then with something more broad spectrum and strong like ivermectin. You can also pick that up while you're at the store. If you see mites, then I'd highly recommend you read this current thread:
https://www.backyardchickens.com/forum/viewtopic.php?id=208346
We look forward to hearing back from you, and thank you for the timely response.