Banshee’s Silence takes precedence over an Acolyte’s Silence, cancelling their canceling of Tenno powers. Has to be running already though. You can’t cast it while being cancelled.
It also cancels all forms of scorpion wires, meaning Infested become a melee-only faction aside from non-scaling MOA goop and flies. I always keep a Silence helminth loadout handy on any frame I regularly fight the Infested with.
Good catch! The Mutalists in question are limited to specific mission types, so I just totally missed that. In my experience the Charger projectile tends to be fairly limited, as it doesn't always seem to be able to reach even if you trigger the behaviour by breaking their pathing to you.