1. That's not a reward, that's a punishment. Physcologically players would need a narrative built around that or other rewards to make it work.1.) The reward is beating the challenges. It's how a lot of games work. It's not like a puzzle game rewards the player by getting progressively easier.
2. Then at that point, they aren't consumables. They're more like spells with a recharge time.
2.) Different perspectives!