I appologize if the question is dumb but I'm not sure I understand why you cope instead of doing 45 degree angle cuts on an inside corner cut for crown molding. Please let me know what are the reasons it is better than the other and what problems you can run into, thanks
Re: Crown molding
Not a dumb question at all.
Consider that your corners are not likely a perfect 90 degrees. A miter cut won't fit those well and will leave an unsightly gap. Properly executed cope cuts will fit tight even if the corners of the room are out of square.