1) No. The expungement order allows you to “truthfully” deny the existence of an arrest record (or even a conviction record) stemming from the expungemed matter.
2) It depends on whether the retailer discovers the expunged charges. Even though the charges were dismissed pursuant to a diversion program and the record of the dismissed charges was subsequently expunged, a possibility exists that a potential employer and/or a information database could discover the charges.
3) Your former lawyers may charge you for answering your inquiry. However, if you make a phone call and ask the question, in all likelihood one of your attorneys will provide you with an answer without charging you further.