The Stun Gun is very efficient for quick takedowns, and the PEPS is quite unstable. You could try using the Tranquilizer Rifle, but it eats your time.
Destroying that Box Guard will be very hard with other weaponry, and a rocket launcher can kill Belltower guards around it.
It is absolutely essential to have an EMP grenade or EMP mine with you. Here's a way to save Malik on Give Me Deus Ex mode without actually killing somebody by your hand, therefore it's Pacifist-safe.
