@
Pat
No
Yes
Maybe, likely they account for approximate stiffness at static ride height as the soft portion of the coil gets taken up just by putting the cars weight on it. I found my B14s to be about as comfortable as stock with the improved stiffness for handling being a nice side effect, they have the same springs to my knowledge and the adjustability is the difference.
Here's the spring range that got published stateside but we might have a different spec than euro and your numbers might account for the bump stops as well.
Front: 2.5 - 4.5kg progressive
Rear: 3.0 - 7.0kg progressive