I made about a gallon of dressing today from Kraft mayo, apple cider vinegar, and sugar. What is the shelf life of this?
Also, what is the shelf life of balsamic vinegar, salad oil, garlic, honey, salt and pepper?
Your coleslaw dressing is almost certain to be sufficiently acidic as to have an essentially unlimited (call it at least a month or two) in the refrigerator. Commercial mayonnaise is acidic enough off the shelf to discourage bacterial growth pretty well, and you have enhanced its acidity with the cider vinegar.
The balsamic dressing--it is difficult to say. It depends on how acidic it is, and that depends critically on the recipe.