Testing Windows user accounts without actually logging into them?
Solution 1:
Q:How can I test that their account is being correctly redirected without logging into it?
A: You can't. You'll have to test it with the user present.
There's no way to test whether or not GPO, Folder Redirection, Roaming Profiles, etc. actually work correctly for the user without logging in as the user. You could certainly run GP Modeling from the GPMC to check that the right GPO's would be applied but there's no way to confirm that without actually logging in.