I am in the middle of painting my living room and kitchen. In the living room there was a wallpaper border that was peeling badly that I removed. The current paint on the walls look good. I was going to sand the area where the border was to blend in the old lines where the border was painted around previously. Should I also lightly sand the entire wall? Or should I just look for imperfections and sand them smooth and then scrub the wall with TSP and then prime and paint? Thank you for any help you can give me.