"Shredding" I have heard (and used ) in regard to surfing and skateboarding.
"You guys were shredding the waves in Malibu last week."
Yes it means being radical, total control of what you are doing, mastering.
"Ripping" could be used for the same thing.
"I really ripped the 360 on that wave."
"Ripper" is a bit different IMHO. When someone says "ripper" I think "Jack the Ripper" an infamous murderer in England. Ripper as in he ripped apart his victims. I dont hear this word used in surfing around here.
- For Teachers