Outlook 2007 Address Book and MS Exchange 2007 integration

Hello,

We have a small company (<10 users) where all users currently have MS Outlook 2007 client installed on their workstation. The MS Outlook 2007 client accesses their POP3 e-mail accounts at the remote ISP.

We are thinking of deploying MS Exchange 2007 so as to gather the e-mails of all POP3 accounts we use into Exchange user mailboxes, so as to have a central and secure view of the e-mails we receive and send out to clients and partners. The dispatch of e-mails is being carried out through the ISP's SMTP server.

We would like to know whether MS Exchange 2007 supports the following usage scenarios:

A) We wish that specific domain users (or domain user groups) have access to particular contact lists in MS Exchange 2007, i.e. a Sales department user would have access to particular sales-related company-wide contacts. A technical support department user would have access to techsupp-related company-wide contacts, and so on. In essence, we need to provide users with access to a "generic" company-wide contacts list and additional set(s) of contact lists according to their department or role.  Is this doable in MS Exchange 2007 and how can we do it ?

B) We need to deploy a software VOIP solution from 3CX (www.3cx.com) to our internal network and we want to take advantage of the CallerID functionality offered by the software, where in every incoming call, the MS Outlook 2007 3CX plug-in checks the Outlook Address Book for the telephone number and if it finds that it belongs to one of the contacts in the Outlook Address Book, it pops up a window with the contact profile. The 3CX plug-in supports such functionality for all contacts in the Outlook Address Book.

*** Question: Does Outlook Address Book contain the contacts from the MS Exchange 2007 contacts lists as I describe it in the usage scenario A we are interested in ???

C) Can we secure the contacts in MS Exchange 2007, so as that domain users will NOT be able to change the details of a contact ? So, company-wide contacts can only be changed by authorised users, whereas the details of personal contacts in the MS Outlook 2007 client of a user can be modified freely by them ?

Thank you for your help.