I see NullPointerException during creation of workspace entity. After debugging I found that apache provided bean validation library used by hibernate on Websphere 8. Exception occurred on preInsert() phase, when BeanValidationEventListener#validate was called.
This exception happends because org.apache.bval.jsr303.GroupValidationContextImpl uses HashMap to execute some validation operations and WorksapaceEntity has hashCode() implementation which assumes that id is not null:

return id.hashCode()

, but on preInsert phase id is null.
I see that NodeEntity has ID declared as "long" primitive, but WorkspaceEntity, NamespaceEntity and ChangeLogEntity has ID declared as "Long" wrapper.
Also there is DNA_CHANGELOG, DNA_WORKSPACES and DNA_NAMESPACES old table names.