Yes, Snapchat allows you to see if someone has replayed your snap story. There is an icon or indicator that shows the replay action. However, this feature might be subject to the privacy settings of the app and the individual's account settings.
Well, it depends on the platform. In general, not all platforms are transparent about whether someone has replayed your story. Some apps might keep track of it for their own internal data analysis but not show it to the user who posted the story. So, usually, it's not easy for an individual to know for sure if their story has been replayed.
Yes, you can find out. Usually, Snap will notify you or show a list of people who replayed your story. But keep in mind that the way it's displayed can change depending on updates to the app.