I think Del Rio is a really good QB. I have seen some brief highlights, and I was pretty impressed. Getting a guy like that to walk-on would be great! Kudos to him too for even considering it.
I don't think this would scare off Bateman. He loves Bama and Coach Nuss. His commitment has always been rock solid. I think it's more likely to affect McLeod if it were going to affect either of the two.
We will just have to see how it shakes out. I would personally welcome Del Rio with open arms. He is a talented kid, and I honestly think he could contribute at some point down the road.