The plants with the white dusting on their youngest leaves look like lamb's quarters to me. I'm always a bit reluctant to ID plants from pictures, but in this case I don't see what else it could be.
I depend on a lot more than just appearance to ID plants for rabbits. Smell, texture, leaf positioning etc. are all part of it.
Lamb's quarters make excellent early season feed, when they are young and palatable. Once they "flower" I don't bother with them much. There is a distinct progression with weeds and I try to feed them at their seasonal best.