The exception would be the wire screens used in litter boxes, like the ones found in the Binky Bunny store. The wire there is pretty tightly knit though. If your litter box is like that it is fine, though a little hay on the top wouldn’t be bad. The cage should not have a wire floor though, especially if she is using the litter box.
As for the cecotropes, you really should never see them. They are not typically put on the ground, but eaten directly from their point of origin if the rabbit is physically able. Occasionally you will see one forgotten about if bunny is stressed or having other issues, but you should definitely never see them otherwise. If you do happen to have a bun that likes to drop them on the ground and then turn around to eat them, this will happen very quickly as well. They don’t tend to leave them laying around for any length of time. Basically, a healthy rabbit will manage her own cecotropes.