Yapp, he already has that scar in the flashback when he wants to go to his parents and join the village's fight against the kyuubi and when he talks to sandaime in childhood days.

I think Iruka is more the Sakura type. Very good chakra control, very good basic jutsus, nice genjutsu and a few minor offense skills. Yet smarter than Sakura-chan.

And he does not need to be a fighting whore, it would serve no purpose. Iruka's role in Naruto is to be the model of the new konoha villagers. His parents were killed by the demon fox, but he was the one who overcame this trauma first and acknowledged Naruto as Naruto and not as the fox child. By giving that `spirit` to the other guys in konoha and teach this to the children at the ninja academy he helps Naruto more than fighting alongside.