Fellow cutter here. not having feeling where the deeper cut is is natural. Basically you cut through the skin layer into the nerve and pigment containing layer. The nerves (which let the brain know things like touch) are damaged and nerves do not regenerate after damage. Regardless of treatment used on the cuts this will always happen when cutting to this level. The amount of scarring depends on the ammount of damage to the area. It doesnt have to be deep just the method and way. if there is damage from bruising and so on to the surrounding area that may result in added scar area to protect that area from harm again. Also if you are cutting in the same place over and over again you are cutting through the original scar tissue and then into the under area so to repair itself there is scaring on the under area and then on to the scar. So then you have two layers of scaring theen you cut again there another scar layer is added I have one spot on my arm where I cut so much there that if I do again I will be cutting bone for there isnothing left but the scar layer and then the bone. I prefer using glue over stitches. Glue wears off where as stitches need to be removes, stitches create larger scar area because they have to be anchors in the good flesh areas where as glue just covers the cut area no need to peirce good flesh for anchoring. Also glueing does not need to be done in a hospital. I can super glue on my own saving myself megabucks in doctor fees, ER fees and so on.