MS Word for Mac: How to make all equations aligned to the left of the document and NON italic by default
On the menubar,you can find Format - Equation options.
There are a lot of options to adjust, but there is no italic option.

If you equations are similar or  have something in common.
You can make a template with non italic and centered to the left(e.g just a =).
Then save it as a new equation,you can insert your template each time.