Chickens should have at least four sq. ft. per bird, and preferably more, in a roofed weather and predator protected coop. It's not a 'sleeping area'! There will be times, during bad weather and predator visits, when the flock might be in for two or more weeks at a time. Too small, and nasty behaviors will happen. Your roofed run can be part of this area, if it's also predator proof. Otherwise, the coop needs to work for the entire flock.
Yes and no. You want to give them around 12" of roost per bird to allow them to get up and down easily, and to jostle for favored spots, but if you just cram a bunch of roosts into a small area, you could end up with birds picking at each other due to crowding, or simply pooping on each other, depending on how it's all set up...
How big is your "sleeping area," and how many birds do you have? If you add more perches, will they be pooping on each other's heads? Too many birds in too small a coop, as mentioned above, can lead to destructive behaviors. The dominant birds may prevent the subordinate ones access so some may sleep outside, subject to predators and extreme weather. They can harm each other and then you may have to isolate birds to deal with wounds. In severe cases you may even have to deal with cannibalism. There is a reason for the "four square feet a bird" recommendation. It's not just an arbitrary number, and it's not just to provide luxury accommodations. It's what the birds need.