Was he a bad guy?
Of course not.
I'm gay for Archer.
Was Kiritugu a bad guy?
He did unforgivable things, but his motivations were heroic and he wasn't technically the villain of the story.
So I don't fucking know.
No, he just had the world shit on him so much that he was desperate to prevent it from happening anymore.
Naw, I'd beat the crap out of my past self any day, because he's a retard. If you ask me Archer's motives were the most relate-able out of everyone.
Archer flashback in new anime written by Gen?