its kinda normal for the cheap green pointers to have the beam not in the center of the aparture.
And theres not a lot u can do about it except realligne the first lens after the crystals
but in most cases the lens is glued to the assy
You will rarely find a greenie that has a perfectly straight beam.
You may find that some of that scatter is due to the beam reflecting off the edge of the aperture (going by your drawing) If it is I would be looking to the manufacturer for a replacement.