At the moment WF Editor gives GUI function to maintain WorkFlow elements but they are limited to Node and Transition creation. It should be able to also handle Condition and editing of their properties.
Patch contains changes to
This depends on http://idempiere.atlassian.net/browse/IDEMPIERE-2022 that extends Node Action with Wait(Schedule). Please apply script and patch from there first.
A PDF guide has been uploaded to http://sourceforge.net/projects/red1/files/ADempiere%20PDFs/Workflow.pdf/download
haven't tested, but from the screenshots it seems like the lists are entered as texts? (action, and/or, operation ... etc)
if that's the case maybe is better to implement the corresponding list in the form.