Handley is poor defensively, but he's getting tries whilst also not completely blocking Hall out of the game. That's important because we're scoring less than 20 points per game across all games this year. At least that edge is a threat.
Walker just looked a really average full back. He has zero presence running the ball back, is pretty ineffectual in the tackle and creates little in attack when we have the ball. His biggest issue by far is his lack of size and strength. He'll never be a man mountain, but in the off-season he needs to put on some serious bulk. I'm completely serious in saying he wouldn't be playing anything other than U19s in Australia. He wouldn't be up to the physicality of the Queensland Cup, never mind NRL (where Hardaker was considered 10 kg too light).
My main fear is that if he continues playing full back the way he does, he'll end up being another kid with promise who gets his confidence blown away and ends up in the Championship or worse. Walker has got talent, but right now for full back is a weakness in our first 17, and he's only marginally better than Golding.