Can't even believe I pulled this off.
And so there's no claims of BS...
Clue 1: He can see your life aura.
-He
can see your life aura, as retconned in "Superman: Birthright", the update origin story. It's the new explaination on his vow to preserve life.
Clue 2: Met his weakness and arch enemy long before being a superhero.
-He came across Kryptonite at a young age, as well as met Lex Luther before becoming Superman.
Clue 3: Killed Green Arrow in an alternate timeline.
-In "Superman/Batman: Absolute Power", he Heat Visioned Green Arrow into ash for attacking Batman. This was an alternate timeline, although he still remembers the act; which hurts him (see Clue 1).
Clue 4: He can track radio signals to it's source (pretty badass).
-His Super-Vision can do this, although not as finely tuned as his Microscopic-Vision.
Final Clue: He's 'done it' in a telephone booth, an elevator shaft, even behind bushes in public (what a freak).
-What did he do? Change into costume.
Kiss my pinky toe.