Dear Brian,
Unfortunately, the "send-to-Excel" functions do not work in OS X because they rely on Microsoft's OLE technology, which OS X does not support.
The Excel workbooks that SAM uses for the send-to-Excel are available on your Mac, so you can at least trace through the formulas even if you cannot automatically export the SAM input values to the workbook. To find the workbook, open the SAM disk image (control-click the SAM icon and then click "Show Package Contents.") The workbook is under Contents, runtime, spreadsheets.
As for the loss diagram, that appears to be a bug. As you note, the graph displays correctly in Windows, but not OS X. We'll try to fix that for this month's update.
Best regards,
Paul.