I'd like to install drywall over the plaster walls in my house (long story why). The walls are fairly uneven though. The room is 22' long and the long wall kind of "peaks" at the center of the room. It's probably a 3/8" difference between the center of the wall and the ends of the wall. Should I deal with shimming the walls to get the drywall perfectly straight or just use 1/4" drywall and let it flex to form to the plater walls? Also, I'm noticing the plaster feels like it's lost it's bond with the lathe in some areas. Either that or the lathe has seperated from the studs. Will this be a problem or will the drywall screws take care of that?