Anyone 100%ed this game? I have questions.

Just completed the story on Normal mode and I am doing Chapter 1 rn on Hard mode, and planning to do a 100% Completion. So I was curious on a few things:

1. Once I get access to open areas, do I have to do all checklists again? (Scanning Mako Springs, Radio Towers, Chocobo Treasure Hunts, etc.)

2. If I attempt the colosseum and the mini games at Gold Saucer, are they adjusted for Hard mode? Same for Chadley’s challenges.