How are you doing crits? Just roll the damage dice again?
So Giovanni is in a box. By my understanding this would grant full cover to him. Would this assumption be correct? If so what would happen if I cast Shatter on the four thugs carrying the box? Would he take the damage or would the box protect him in some way? Also would the box be considered being carried for avoiding the damage from the spell?
So, to make it clear, unless otherwise stated, Nicolo's attacks are typically to disable rather than kill. So his default is nonlethal. He might kill, if he has to, but he'd rather not.