I'm not in the KC area, but east central Illinois. I can answer some of your questions.

Not sure of all your winter weather, but I will assume that you get below freezing many times during the winter months. If so, dig up the elephant ears. They just don't do well in these long-lasting temperatures. Dig them, let them sit out for a day or two to allow the soil to dry a bit. Knock off the soil and put the bulbs/rhizomes in a coolish, dry place. Ideally, you would have mesh bag so that too much moisture does not collect and rot them.

For your perennials, some of them do better cut back to the ground as the foliage is somewhat delicate (obediant plants) and they would get messy/ugly as a result of your winter weather. I leave my coral bells for now and cut them back in the spring (you can do that with many plants, I just don't like to look out the winter at plants that are laying down with the weight of snow). I have many of my summer bloomers already cut back. The fall ones, like asters and mums can be left until after you have a couple of heavy frosts. Again, there are many gardeners who leave a lot for their spring chores, I don't do that. It's a matter of what works for you.

Spring blooming bulbs go in the ground now. You want them to get settled into their new home as soon as possible. Be sure that the area where you plant has lots of loose soil. If it doesn't, then dig it up now and let it rest for a couple of weeks, then do your planting. I have had regular good results with a bit of bone meal in the hole (worked into the soil a bit) that will help with root health. You don't really want a full nitrogen fertilizer now, that should be done in the spring as new growth shows. Even then, do not use a liquid fertilizer, I use a blood/bone meal combo in the spring for lots of my plants.

Here is a link to the Missouri Extension site that has lots of information. The Kansas one is good, too, but this would have more appropriate information for your area.

Ask more questions.

Jim

Here is a link that might be useful: Missouri Extension site

Coneflowers can be allowed to stand up through the winter. The seed heads will be used as a food source by small birds, like finches and chickadees. Or, you can cut them down and clean up the bed. It's up to you.