Just as improvement: I just found that Eclipse designer allows me to produce invalid Bpmn XML file, causing the error
org.activiti.bpmn.exceptions.XMLException: cvc-id.2: Há várias ocorrências do valor do ID 'xyz'.
The error is that it allows me to have a "service task" with ID "xyz" and a "process" with ID "xyz", causing error at deployment. Would be nice if designer enforces that all ID are unique in one XML.
You mean you would like it to automatically change ids? I don't think that's a good idea - as you write queries using that id and assume it is what you set while designing it.