Hi KillerQueen,
While I don't have a Mac and (therefore) don't use Safari, I have seen various posts over the years with reports of problems using Safari.
I can only suggest that the Firefox browser is often reported by the Mac users to overcome most of the issues reported, and Auctiva often coaches and/or addresses issues in the context of using either Internet Explorer or Firefox.
Installing the free Firefox browser for Mac might be your best alternative. However, you might want to open a Support Case (use HELP link at page top) and ask if that's the current recommendation, or they have any suggustions / settings for use of Safari.
Note, there are some obvious restriction in using tools on the site that are Windows Only/IE, e.g. things marked as ActiveX like the Image Upload "Drag and Drop" feature.
Does that mean you should run out and buy a PC, heck no.
Danno