I agree with @Folly's place - wire flooring is not easier to clean than a smooth, waterproof floor with plenty of bedding on top.
I'm assuming your plan is to keep them and their coop inside the house? Will they have a run and access to the outdoors?
I wouldn't feed just corn. What chicken feed can you get there? Is there a pelleted or crumble version? I'd use that and add niacin (peas, nutritional yeast). Or you can even stick with the starter crumble and niacin.
By the way, placing larger items like rocks or lumber on top of the apron defeats the purpose of an apron. You want the predator to dig where the apron is not around the outside of it. You'll want something diggable on top like dirt, mulch, or gravel. I think some people have even left it on...
I don't think that was a waste of time. The apron will keep out foxes, domestic dogs, and other digging predators and pests. And it might even deter raccoons, opossums, and cats. And as @swamphiker said, no hawks are getting in there with that roof.
I'd call that a predator-resistant run. Not sure how much covering the larger gaps would help. Weasels can easily fit through the larger wire mesh and raccoons can at least stick their hands through.
Here is that thread if anyone is interested: https://www.backyardchickens.com/threads/proper-wing-clipping-to-aid-in-containment-with-perimeter-fencing.1261276/
Yes, I've heard that some chickens can still fly if the primaries are clipped on both wings. Muscovy ducks are heavy birds that don't fly much in the first place and I've found they aren't as eager to fly over fences.
@centrarchid conducted an experiment to see how high his chickens could fly with one wing and both wings clipped. It showed that clipping both wings was more effective.