Steel will is more of a skill to assist in the resisitance as well as activation of masteries. Like an attack skill is used to hit someone and opposed by the evasion skill, Steel Will works the same way. Though the description is vague and needs serious clarification, it is more a focus of will than anything else.
Which doesn’t relate to fear, superstition, and rationalization at all. Fear is an emotional state, and while Steel Will may help you resist a magical ability attempting to force you into feeling someting you normally woldn’t, it doesn’t shield you from natural emotions. To apply Steel Will to Fear Checks would be paramount to adding Steel Will to anger, love, etc.. in essence it would imply that characters with a high Steel Will are emotionless, which simply isn’t true.
To answer your question about 1 1’s and 6 6’s, they count as 2’s or 12’s.