From Excel Macro Security - www.excelfunctions.net:
Macro Security in Excel 2007, 2010 & 2013:
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The different Excel file types provided by the latest versions of Excel make it clear when workbook contains macros, so this in itself is a useful security measure. However, Excel also has optional macro security settings, which are controlled via the options menu. These are :
'Disable all macros without notification'
This setting does not allow any macros to run. When you open a new Excel workbook, you are not alerted to the fact that it contains macros, so you may not be aware that this is the reason a workbook does not work as expected.
'Disable all macros with notification'
This setting prevents macros from running. However, if there are macros in a workbook, a pop-up is displayed, to warn you that the macros exist and have been disabled.
'Disable all macros except digitally signed macros'
This setting only allow macros from trusted sources to run. All other macros do not run. When you open a new Excel workbook, you are not alerted to the fact that it contains macros, so you may not be aware that this is the reason a workbook does not work as expected.
'Enable all macros'
This setting allows all macros to run. When you open a new Excel workbook, you are not alerted to the fact that it contains macros and may not be aware of macros running while you have the file open.
If you trust the macros and are ok with enabling them, select this option:
'Enable all macros'
and this dialog box should not show up for macros.
As for the dialog for saving, after noting that this was running on Excel for Mac 2011, I came across the following question on SO, StackOverflow - Suppress dialog when using VBA to save a macro containing Excel file (.xlsm) as a non macro containing file (.xlsx). From it, removing the dialog does not seem to be possible, except for possibly by some Keyboard Input simulation. I would post another question to inquire about that. Sorry I could only get you halfway. The other option would be to use a Windows computer with Microsoft Excel, though I'm not sure if that is a option for you in this case.