Susan, I can't answer all of your questions, but I would relax on the rust stuff. Don't think about throwing them in the trash, there are some beautiful flowers waiting to see the sun.
And winter is just beginning - there are a lot of days between now and spring.
I have even had rust in my northern garden. I just put up with it, and hope it all dies over the winter. I cut back the all the plants in the affected section of the garden and tossed it out with the trash. (didn't mulch them) Granted, my harsher winters can kill more rust that yours can, but for now, I would relax about it.
I don't pay much attention to prevention at this point, but I know there are others on this forum that live in approximately your zone and can help you better than myself. They will probably chime in. But for now, I wouldn't waste a lot of energy worrying about it. In reality, the majority of daylilies are pretty hardy, that is why they are so popular ~j
