On point 5, thing is as a programmer (any career actually) with years of code experience, you just know the possible cause for any bug, and what function/class is at fault.
To elaborate, debugging is basically "applied memory recall". When you see a symptom, what happens is that you start guessing how it could have manifested. Sheer experience basically gives you better guesses.
I've been able to debug more effectively than my coding skill level would imply by dint of my better recall ability.
I've been able to debug more effectively than my coding skill level would imply by dint of my better recall ability.