If you find a construct you can edit in the process diagram, but doesn't get synced to the BPMN, then that's a bug. Please report a case like this to us, by filing a Jira issue for the Designer component and we will look into it. Regenerating the BPMN for the constructs supported and dropping non-supported output is, however, a feature.
2. Why can't I install Activiti Designer with Eclipse 3.6.2, Eclipse Java EE and/or plugin <myfavoriteplugin>?
Noticed behavior: Unable to install Activiti Designer into a different distribution of Eclipse than Eclipse Classic 3.6.1, such as Eclipse for Java EE, Eclipse for RCP, Yoxos, SpringSource Tool Suite, etc because of plugin versions conflict(s).
Resolution: Pending, we are working on becoming more compatible with other plugins
Workaround: Use Eclipse Classic 3.6.1
We currently only support installation on Eclipse 3.6.1 Classic. You can download the Eclipse distribution from here. There is a known issue in Eclipse 3.6.2 where the properties view is not correctly synchronized with the diagram. This means that if you click on a node, the properties view is not correctly changed to show the properties of the selected node. We are affected by this bug and cannot upgrade due to it. We are monitoring resolution of this issue in order to support updated versions of Eclipse
Some other distributions of Eclipse and especially some plugins may require other versions of plugins that are incompatible with the ones we require (particularly, WST and EMF). We are looking into loosening our requirements so Activiti Designer can be combined more flexibly with other plugins where possible. We hope you understand it's nearly impossible for us to test with all different distributions and plugins out there, but we are working on our part to have less stringent requirements to avoid as many problems as possible. Our aim is to be compatible with the most recent version of Eclipse where we can, so you can be up to date as a developer.