I believe I’ve have found a bug in the Ecobee binding related to being able to configure it via Paper UI. Please uninstall the version you’re currently using and try this one. You could install it like
bundle:install https://dl.dropboxusercontent.com/u/4286376/ecobee-binding-xml/org.openhab.binding.ecobee-1.9.0-SNAPSHOT.jar
bundle:start <the ID of the bundle just installed>
The difference ought to be that you should now be able to configure it via the Paper UI.