1. If a movement comes out of the Hopper, does it go back in?
No. Once it's out, it stays out.
2. Isn't there a possibility that 3 gymnastics pulling movements (bar muscle-ups, chest to bar pull-ups and toe to bar, let's say) could all be pulled out of the hopper for the same WOD?
Yes. It's a possibility. It's unlikely. But it could happen. Drawing Dead Lift, then Snatch, then Clean could also happen. Unlikely, but possible. That's why this event is very different.
4. Do the athletes in the later heats have an advantage since they get to see the athletes in the earlier heats?
Perhaps. If we can figure out a way to sequester the athletes waiting on their heats, we will.
5. What if, by luck of the athlete draw, one heat gets stacked with all the strongest athletes?
Could happen. They'll have to step up.
6. What if the "best" athlete doesn't win?
So be it! This event is a combination of skill AND luck. It's about how the cards fall and how the athletes respond. It's the unknown and unknowable. If you have to know exactly what's going to happen at a competition, that's cool, but that's not this event.