Not seeing a difference after changing the CFG file.

Weapon durability still drains the same amount after changing %. How can I adjust?

Hey, attach config, list of ALL plugins, to see there is any interference, and also did you assign the specific permission, to apply the changed usage of durability?

Im sorry, how do I assign the specific permission server wide?

You can assign the permission to the players via ingame with a permission manager plugin, or carbon itself. As i see you have adminmenu, that shall be capable for that to assign a default permission to a standard role, look up for that plugin description how to or configure another plugin to give a permission as reward, etc... 
Also i meant the plugin list like o.plugins or c.plugins, which list them into a server console.