Can anyone tell me who these people were? 

1) The woman who apparently is Min Yong Joon's boss at the end. She comes into his office together with the school's guard.  This might be actress Shim Dal Gi playing character Shin Hye Won in the cast list but I don't remember her role at all.

2) The old man watching Bongseok save people from the building on tv at the end. I vaguely remember his signature gesture, but have completely forgotten what he was all about.