It looks like the nut or nuts were loose for awhile and no reinforcement allowed the metal to flex and crack. Possibly. Fix that area and add the plates and you should be good to go.
Yes definitely. When I got the car I pulled the buckets out and discovered the guy put a piece of tin that he had formed around the floorboard. Kind of a shoddy patch work. I figured there must have been some support for buckets.
Strange though, you'd figure that they would already be in place, that way when coming down the assembly line it would be ready. "Buckets or a bench in this one".