I don't have the users password yet so I can't answer number 1
2. Using the share calendar feature of Outlook. One user is Outlook 2013 and the other is Outlook 2010
3. I used my account and I used Outlook 2013
4. No not that I know of. Not many people use Mac's hear but the Windows users work fine
I won't get the computer again until possible Friday but I will check OWA hopefully before then