For #1, a picture would help a lot. It may not be anything of importance, but not possible to tell from description.

For #2, 3 +1 with m4dm4n. You have to map out beard growth patterns on your face and neck and then you will have a better idea of what to do.

For #4 It is a way to shave that some find works for them. You can only try it and see. ATG passes are tricky and strategy can depend on the razor you use. I have been told to keep the angle for ATG passes low. Cuts and stutter and irritation are cured by good technique. I am still working on ATG. Very tricky. There are places (upper lip) I won't even try.

For #5 Roughness is a function of the sharpness of the blade and you choosing the proper angle of the blade. Practice is all one can do. Go slow, take small strokes and think about what you're trying to do.