I installed my Neu\Steins a week ago, at the lowest setting all around..
- front is about 2.5 finger gap (25.5" fender to ground height I believe)
- rear is about 3 finger gap

seems kinda high still...only a bit lower than my OEM sport suspension. Also, the ride quality hasn't really improved as well (both comfort and handling)...and over roads, I can feel even small bumps in the road.

1. If I get H&R sport\Neuspeed Sport\or Vogland springs, how much lower will I be?
2. Any way to decrease the harshness of the ride?? Everything installed seems tight, and mechanic told me all the control arms and everything are still good (replaced half year ago). But I hear some creaking noises from the rear sometimes over bumps, and "spring" noises too (from front and back)...could it be sway bar links?

Going to a different spring will lower your car, but it won't take out the harshness. That's the property of the shock. Changing to a different shock will eliminate that.

My recommendation is for KONI shocks if you're looking to retain ride comfort.