If the attack program had a staging and Decker did damage, the damage would be the staging plus the net successes. If the Black IC hits, it gives the net successes in damage to the deck. If 0 net successes, attack misses. If the Utility had a staging, the damage would be base staging plus net successes. Each point of Hardening gives the decker an auto-success.
Sensors only take part in play against other deckers.
The Sensors rating is used as the number of dice for perception tests in the matrix. Change the target of IC resisting Sensor programs to Sensors rather than Evasion. Each level of the spell adds an extra die to the caster's Initiative and 1 to the caster's Reaction. The number of successes scored on the spell success test is irrelevant. Note that initiative die bonuses do not stack.