Hey Turi,
You are allowed to give "impersonation" privileges to users under qube! I suspect since all of your users will probably need this feature, you'll want to enable it by default by modifying the supervisor's qb.conf or using the configuration gui on the supervisor to adjust the default permissions per user.
Impersonation allows a user to submit a job as another user. This is allowed for situations where security isn't as tight since you are basically allowing a user the ability to run their programs as anybody in the facility. Keep in mind though, this is all logged in the supervisor so impersonation can be detected after the fact.
qube! as a rule normally assumes your network is protected at the boundaries security wise. This is a reasonable assumption since most companies use NFS and other very security weak mechanisms NIS to move data around efficiently rather than securely. Sort of like the time vs. space inverse proportionality when writing software. Since the network is normally contained, a studio will normally just use NIS, ActiveDirectory or LDAP for authentication. However in your case, you'll have to do what we do here, which is to allow impersonation and to require the user specify their user's name and domain.
Thanks,
Anthony