Red Dye #3 is not commonly used in the United States anymore. Instead, Red Dye #40 is used and works just fine as a safe replacement.
Brominated Vegetable Oil is used to emulsify flavor oils into water and is commonly used in citrus soft drinks. Sucrose Acetate Isobutyrate and Glycerol Ester of Wood Rosin are both be used for the same purpose.
Potassium Bromide is added to flour to strengthen dough, allowing for a greater rise during baking. It appears that Ascorbic Acid (vitamin C) can replace much of its use.
Propylparaben is an antifungal preservative that is used in packaged baked goods to prevent mold. There are other preservatives that can be used, but it sounds like parabens are the most effective for preserving non-acidic foods. I assume that propylparaben will be replaced by some other paraben.