Ciaran,

Regarding conference rooms, we found a bug in MAPI that prevents them from working. They work fine in EWS as it's properly returning the info for domain conference rooms. MAPI, however, is not. We're looking into it and hoping we can get it fixed in the next BETA.

As a workaround for now -- until we can get the bugs worked out -- you can create a new user and use their calendar as the "domain resource" -- just share their primary calendar with everyone in the organization, giving control as needed to your users. Secondary calendars can be used as domain shares as well.