Bad textured walls in my house do I need to take special precautions when Graphite Insulating Lining Paper over such poor surfaces?

Not really, just make sure the walls are clean, dry and solid. If the texture is very deep as with some decorative plaster effects it is advisable to sand down the high points and use extra adhesive to help level the surface. We would advise that after hanging the first drop of Graphite Insulating Lining paper, stand back and make sure the results are satisfactory.