We have several Windows workstations which are shared by multiple users. I'm currently considering a scheme where users have their own user accounts and profiles, but they share the same Desktop and Documents folders. Our users are used to sharing things with each other by saving to the desktop, so this wouldn't require any training. My questions about this scheme are:

1. Is this a terrible idea? The fact that I don't see anybody else doing this makes me think there's something wrong with it, or there's a much easier way to achieve what I want.

2. I could probably do this by logging into each account, going into properties for the Desktop and Documents, and choosing Location → Move. Is there a way to configure the computer to do this automatically on all new user accounts?

Scenario

Currently, the workstations log into a single local user account. The only sensitive data is stored in a few applications like Outlook. We do not have a domain and have no plans to create one.

As far as I know, we can't simply password-protect Outlook profiles because we use Exchange in cached mode. OST files can't be password protected, and since we use cached mode even if we enabled "Always prompt for credentials" on the Exchange account, a snooping user could just hit cancel and look through cached email. When searching online, the advice to protect Exchange accounts seems to always be "use separate Windows accounts".

Since users love saving everything to their desktop and that's how they share files with each other, using separate accounts would require everyone to remember to put shared documents in special shared folders. I foresee this just causing too much friction to be worth it.

But, if I could create multiple accounts that share the same Desktop and Documents folders, users would be able to share files simply by saving them to the Desktop or Documents folders, and yet sensitive per-user data would still be stored in AppData and therefore be protected by ACLs and the Windows account passwords.

The workstations are running Windows XP, Vista, and Windows 7, and running any version of Outlook from 2003 all the way through 2013.