Dayliles are somewhat drought tolerant but they flower better with good watering.
Most likely it is because your daylilies have too little or too much water. If you are concerned by the soil, have it tested and ask the expert what amendments you need for your daylilies. Most daylilies are very hardy.
Yes. They will eat the flowers, but not the leaves.
Rabbits and deer eat daylilies. Even cats will chew on daylilies.
There are daylilies in most temperate locations.
Yes. Daylilies can be grown in pots.
Daylilies are very hardy. The pests that bother daylilies are rust, thrips, spider mites, snails, and crown rot.
Iris is toxic to cattle but daylilies are not toxic.
Daylilies are not poisonous. In fact, all parts of the daylily are edible. The Chinese use the buds in stirfry. And you may have to spray the daylilies with repellant to keep deer and rabbits from chewing on them.
Most daylilies are shipped bare root. Generally they are wrapped in damp newspaper to keep them moist from shipping. Because they are so hardy, just put the roots or tubers in water for a day before planting them in your yard.
No you do not have to mulch your daylilies. Most gardeners do to cut down on weeding and watering.
no
Daylilies have a herbaceous stem. The old stems die and gardeners should compost them.