Yeah, I agree. Felicity, thus far, is the most important relationship for Oliver, because it's his relationship with her (whether platonic or romantic) that's driven his change. She tells him to find another way, he does. She tells him to keep fighting, he does. She tells him that he's waiting around to die in the cave and that she wants more out of life than that, he tells Diggle he doesn't want to do that. He tells Felicity he can't beat Ra's, she tells him he's a different guy now, and that guy can. She keeps him going when he wants to give up, like his own personal frickin' Tony Robbins.