Will ARD always be a part of your past in the background with law officials even when you successfully completed the program?

If you received ARD and your record was expunged, you should not have a criminal record when your official history is produced by the FBI or PA State Police. It may still appear on some private background check website that the basically relied on your arrest record and never removed the information. Every DA office will know you received ARD so you cannot get it twice.