The perk idea is great, I'm hoping perks will eventually become more about customizing the experience and less about +10 guns, +10 wellness, +10 stamina etc. Perks should be more than just stat boosts.
There are plenty of ways to lower difficulty, including turning off zombies. There is a creative mode. The survival game mode should not have a built-in "feature" that lets you bypass the game's main challenge.