OK, I think what you want to do is sort of possible, having said that I've never tried it. There's an option to change the logon credentials used for managing devices to be a user-level rather than device level:
You then set up individual user login accounts to use (as suggested in the highlighted box). I'm guessing there will then be an option when you configure the device to change the credentials from Device to User. I suppose that this way whenever you change your password you only have to change it the once rather than for 100s of devices.
Regards,
John