RaceFaceNext 20mm Riser Handlebar

I like my handle bar shorter then the suggested cut length. can i cut beyond the suggested length. what would it do to the handle bar f i did?

Is this 10 or 20mm rise?

How much can I cut off each end?

whats the difference between 31.8 and 35? i have a 31.8 easton heaven, will this still fit?