+3 on the 22 1/2 degree angle. To glue the angle, since it is awkward to clamp you can just use an ample amount of glue and just use masking tape across the joint to hold it together until the glue dries. My thoughts is our cats wouldn't use something they had to jump through a hole to get into. I don't know what your thoughts are on the pull out. If you mounted it on slides, the cats wouldn't use it with it moving and the hardware wouldn't take to the litter. I believe I would just make a door and just slide the litter box in.