I was down until you mentioned Halloween Candy. That is when I walk out.
Yes. I don't think it is asking a lot for a leader to spend time (real time, not supervisory) performing various roles in the store, especially the roles that will be dependent on their planning skills.
Every company I have ever worked for, I made sure to stress that I would not work there unless I had at least one full week of "true" associate experience. In my experience, management training can start off in the wrong way when they are locked in the supervisor bubble. Once you are locked in that bubble, it is very hard to get out and it can be detrimental to the business as well as team cohesion.