I eat dried fruit each day. some are sulfite-free. do sulfites prevent mold or bacterial growth on the dried fruit? if so, is sulfite-free more risky?

No.: Sulfites do discourage some bacterial growth, but they are mostly used used on fruits and vegetable to prevent unpleasant browning, and on shrimp and lobster to prevent melanosis, or “black spot”. "sulfite-free" is more of a marketing tactic than anything else; but some people are allergic to sulfites, and must avoid foods and beverages that contain them.