I'll try to answer one at a time :)
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* Evaluation bpmn2 and error:
18:25:01,752 ERROR [stderr] (http-localhost-127.0.0.1-8080-4) org.eclipse.emf.ecore.resource.Resource$IOWrappedException: Feature 'script' not found. (inputStream://dummyUriWithValidSuffix.xml, 33, 19)
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This issue was recently resolved: https://issues.jboss.org/browse/JBPM-3728 and you have to either wait for a new jBPM version or build jBPM from its master branch to get the fix now.
You have also an option to manually fix the problem by changing all:
<tns:onEntry-script .... >
<script> .... </script>
</tns:onEntry-script>
to
<tns:onEntry-script .... >
<tns:script> .... </tns:script>
</tns:onEntry-script>
(same for onExit-script nodes) and then import it into Designer.