Re: Studs becoming visible through the drywall....
I don't remember the exact term for that, but what is happening is the framing is wicking the cold to the interior which then condenses moisture from the warmer room side air. The moisture attracts airborne dust and dirt, causing the shadows on the walls and ceiling. There should not be enough moisture build up to cause damage, only enough for the dust to collect and discolor the surfaces.
Periodic cleaning and repainting will keep the streaks at bay. Not sure if there there is a cure for the cause that is economical or aesthetic.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!