Hi,
I understand your situation, but I don't think that working with Offline Vaults on laptops that are always changing owners is a good solution. As you mention, it takes lots of effort to create the Offline Vaults. So, once the Vaults are synchonized and stable, it can be that the laptop needs to be re-staged again.
As "the users don't need all the archived data with them", is it not beter to look for the OWA or RCP/http options so they can access their archives remotely via the internet?
As far as i am concerned, you can not include/exclude seperate folders for Offline Vault use.
Greetz,
Rudy