Accoun/Login for impersonation of any Exchange user

I have a developer that would like a Domain login for connecting to Exchange 2010 i.e. ‘Test User’,  that has the minimum rights for user impersonation for any user, and rights to view the schedule for any Room Resource that is contained in a Room list, i.e.“Test Managed Conference Rooms"

We would like a Powershell script that did this in Exchange Command Shell which would be optimal, although some combination of PowerShell and specific Exchange Management Console operations would work as well.

So basically we would like an easy way to have a customer of ours setup a login with minimum rights on their Exchange server for us to use on our Exchange Web Services API so our system can Create, Delete, Update, and View Exchange Resource schedules for any Resource.

Any help would be greatly appreciate.