IMHO Membership of "QlikView Administrators" is only used to verify if you have access to the QMC. All other (internal) stuff is done by the QMC service account. And as QA member, you won't get any service account permissions on filesystem objects.
Answers to your question: NO (directory access) and YES (open QMC and launch tasks, define tasks, see documents lists, change sttings and the likes)
For example, on the QlikView Enterprise system I'm currently looking at, the group "QlikView Administrators" has no rights to any of the directories that were created to harbour documents, QVD's, script files, batch jobs or anything else. However, since most IT guys belong to both Domain Administrators and QlikView Administrators at the same time, they will be able to access all QlikView files anyway.
BTW the QMC gives you permission to control only few QlikView objects, mostly documents, tasks, users and settings. But not QVD's for example.
that will help me in my argumentation with the IT_folks. So the fact that they are necessarily part of that local group "QlikView administrators" does not give them any access rights - so I guess it's okay that, in addition to that group, the IT_folks also have security access to that directory.
Almost correct. What I'm saying is that whether or not those IT guys are member of local group QlikView Administrators (which indeed gives them almost no rights at all, only access to QMC and maybe some installation folders), they will have access to all directories in any case because they usually are member of the global group Domain Administrators as well. And the Domain Administrators group has access to everything.
It's difficult to give you good advice because every environment is slightly different. Don't hesitate to discuss this with your IT administrators before finalizing your requirements. They know the details of your infrastructure.