Here is my problem:

My company has multiple locations. We store contact information at each location for a service we provide. There are some customers that use the service in multiple locations. I'm trying to get devices to store this data at 10 of our many locations. I would like each location to be able to access one another's data efficiently to eliminate data redundancy. My company has many BlackBerrys and a BES. I thought that old BlackBerrys would be the best solution instead of our proposed solution of personal electronic organizers because those have no data backup or sharing abilities. These devices would not be used for voice at all but only the data connection to store data on the server. I have a few questions about the limitations and capabilities of BlackBerrys before I present this to my boss as a feasible solution to our problem:

1. If we have a BES, is it possible to restrict the contact information to only 10 locations so that it isn't shared to the rest of the company?
2. Is it possible to block all other functions on the device except the address book either via password protection or IT Policy? Basically, I want to ensure that people aren't using the device for games, sms, email, etc.
3. Does anyone see any disadvantages to my proposed solution?