If an app needs to declare the permissions it uses when you install it, and then you can choose whether or not to install it based on that, why would some permissions not be granted by the OS? If the user accepts those permissions, the OS wouldn't know any better. The best way to do this would probably be to add an option where the user needs to specifically decide to allow these high-security permissions, and then an extra warning before installing each app that uses any of these permissions.