Isn't the North endzone set up so another couple of sections can be added as bookends to the current second deck? I believe so. I don't really believe the stadium ever has to be bowled in, just make the endzone building and locker room first class.
Yes. The standing areas on either side of the Scoreboard Club seating were poured like the seating area of the State Level Club that is just below the Scoreboard Club. The drink rail where the shadow people are standing in the photo is where seats would go for a future enclosed club level.