It also elevates your eyes. It like my eyes dead center. The wider the screen, the taller it gets. In my case 13' wide screen mounted dead center vertically from 1st row would have put the screen in the ground. So the plan is to make the money seats what would be 2nd row on the risers and leave space below for overflow.
The railing I think is a code / safety thing. I'm not sure how far a drop is advisable before a railing is needed.
I was thinking of doing something like this, but without the 2 front chairs.