Couldn't say what breed I think the one in the first pic is a roo, the white one, and possibly the one in the fourth.
I wouldn't get rid of any suspected roos yet, because they still need time to mature. Once they start to get aggressive you'll know for sure. Cute chicks!
They look like mutts mostly, but it is still hard to tell.
I hate it when the 50/50 never works out. I ordered 2 Campine hens from a hatchery, and I got two roos (Anybody want em'?). Possibly the same thing happened to my WFSpanish, those roos are pretty cool though so I won't be to upset if they are.