New child mantenance rules

Have just been reading about the new rules (using gross income, charging parents for collection etc) and am somewhat confused.
I''ve just opened a claim for the CSA to re-assess based on an out of date arrangement.
reasons I''ve asked them to re-assess:
1) ex refused to attend mediation to discuss family based assessment
2) ex having children less than 52 nights (existing maintenance arrangement is based on more than 52)
3) ex''s salary increase.
The CSA have not said that I will be charged for them to pursue my claim or the 20%/7% charges for collecting the money on my behalf.
My questions are:
1) once the new rules roll out to include NRPs of 2 children will the percentage charge automatically start or will the fact that my case is settled (if it is) before the rules apply to NRPs of 2 children mean that there is no charge?
2) As the new rules consider gross income, and my ex pays 1/5 of his salary to pension at present, would he need to pay more money on the new system?
Thanks, everyone.

Not sure about question one but think it will only apply to new cases.

Think I have read that pension contributions will be excluded from new scheme in same way as current scheme so it will be gross income after pension contributions.