Hi, we are updating the Designer documentation and you can see the latest here: https://hudson.jboss.org/hudson/job/jBPM/lastSuccessfulBuild/artifact/jbpm-distribution/target/jbpm-5.2.0-SNAPSHOT-docs-build/jbpm-docs/html/ch10.html. As far as the properties, this is still on the todo list and will be available in the docs before the jBPM 5.2 release. For now if you have any questions this is a good place to ask :)
Hope this helps and thanks for using the web designer.