Hi Christian,
As you know, Office 365 Online service has different Plans, for P1 plan, users will use Exchange Online (P1), and E plan users can use Exchange Online (P2), therefore it's not available to move emails and accounts between the different plans of Exchange Online service.
For this scenario, you can use .PST file to move data between accounts. Here is the detailed information: http://help.outlook.com/en-us/140/dd401503.aspx
For the second question, the license for the Office Pro Plus does not include Mac versions.
Thanks,
Bourne Zhang