Only "QlikView Administrators" is created by the installation program. This is still the case in v10. Members of "QlikView EDX" may trigger EDX tasks, members of "QlikView Document Administrators" can be granted delegated/restricted access to QEMC (v10) and the mere existence of this group improves QEMC performance in v9, members of "QlikView QMS API" can interact with the v10 Management API.
EDX integration changed a couple of times since v8.x. I think it is still the same since v9sr1. You really ought to upgrade to at least v9sr5 to avoid some memory leaks in the earlier v9 releases.