tomcat.enable.debug is used in setup/build.xml when tomcat Tomcat is installed. if If the property is specified (whatever value), the following line parameter 'jpda' will be added at the beginning of the catalina.sh:
JAVA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8787"to the start commands in Tomcat's 'startup.sh' and 'startup.bat' scripts. That will cause the remote debugging service to listen on port 8000.
skip.deploy.activiti.modeler=true set this property if the Activiti Modeler fetching from net and deployment must be skipped.
Unless before a release or explicitly working on the Activiti Modeler, it's advised to set this property since sometimes a version matching the current trunk version isn't uploaded yet, causing the demo setup to fail.
mvn.executable=mvn.bat on windows you have to set this property to make the calls from the ant build scripts (distro/build.xml and qa/build.xml) to maven work.
In order to have BPMN code completion and validation, import BPMN's XML Schemas from activiti-engine/src/main/resources/org/activiti/impl/bpmn/parser into the Eclipse XML Catalog, which can be found in Preferences --> XML --> XMLCatalog.