Looks much better in terms of breaking up the space.
As far as the peepers, you can leave them on for a while as far as I know, as long as you check them regularly for any caused irritation or damage.
Not sure how realistic it is to modify your coop to make it larger, given the style, unless you're planning on blowing out a wall or something? A 2nd coop may or may not work out - in some cases the birds will ignore one coop and all stuff into the other, whereas in other cases they will split up and use both. Hard to say what will happen if you try it with your flock.