Chocolate is not an emulsion, it's a suspension - there's little to no water in chocolate.
Adding water thickens/seizes the suspension.
Adding a fat that is liquid at room temperature reduces crystal formation in the chocolate as it cools, leading to chocolate that is soft, does not snap, and may not be as stable. (Anhydrous butter fat is added to chocolate in industrial production to make it more stable but I don't know about using it in small quantities in hand production.)
I can't see how adding the balsamic to dairy butter or olive oil will work. Maybe to cocoa butter. I know that many "raw" chocolate makers add agave syrup to their chocolate and agave syrup has a high water content and they are still able to temper the chocolate, but they are not adding any other form of fat other than cocoa butter. So that might work with you.
You want to make flavored, solid bars, right? Most people using ingredients like balsamic and olive oil are making ganaches and then covering them. You can do that in bar form - as Zotter does.
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@DiscoverChoc