I like to have a bunch of widgets on my desktop but that means I have left room for actual items from the Desktop folder. Instead of Icon view is there a way for me to list everything in a list view?

AFAIK no; one alternative is to reduce the size of your Desktop folder by moving some of the applications in it to the Panel; another might be to reduce the default size of icons on the desktop generally.

Bear in mind that Folder View is itself a widget just like all the others. It just happens to point to a folder (which may or may not be the Desktop folder).

You could switch from using a folder view for the desktop to default desktop (right-click on desktop -> folder view settings -> change Layout from Folder View to Default Desktop) and add either a folder view widget or shelf widget pointing at the desktop folder. This way the desktop icons are organized within the widget and won't crowd out your other widgets.

If you have a lot of widgets on the desktop and are having troubles keeping them organized, you can try using the Grouping Desktop with its widget groups to help organize things (see http://userbase.kde.org/Plasma/GroupingDesktop)