Hi Sam,
1. You can setup a persistence env with JBPM using several different configurations. For example in one case you may want to use the same schema for all persistent info, in another case you may prefer use the schema jbpm for the jbpm data and the schema task for the human task info.
So much flexibility is possibile thanks to several persistence.xml files.
2. The two persistence.xml that you cited (jbpm-5.3.0.Final-human-task-war and jbpm-human-task-war-5.3.0.Final) are the same file: jbpm-human-task-war-5.3.0.Final is a .rar that contains the war file.
The two options are now available because the default transaction manager lookup no longer works with JBoss 7 (as its jndi name has changed) as explained in http://kverlaen.blogspot.it/2011/07/jbpm5-on-as7-lightning.html
When you customize your installation you will choose the proper TM for your system:
- org.jbpm.integration.console.JBPMTransactionManager for AS7
- org.hibernate.transaction.JBossTransactionManagerLookup for AS5
btw if your goal is to using a different db from h2 you should looking at http://docs.jboss.org/jbpm/v5.3/userguide/ch.installer.html#d0e597 where you can find all the info to configure a working system.
Regarding your second post the answer is yes, you need to configure that persistence.xml file if you want the JBPM console continues to work.
cheers