Hello Kevin,
The cuts made when shear scraping are *very light*, only tiny wisps of shavings come off. Shear scraping is not designed to remove lots of wood... Think of it as a surface perfection technique. No death grip is required and only a tiny amount of torque is applied to the handle...
The edges of the scraper I use have been slightly rounded, so there is no damage to the tool rest. There are many other types of shear scrapers available with machined flats that orient the shear cutter at the proper shear angle. Using one of these presents a flat machined surface to your tool rest. These are available if you prefer... The Kel McNaughton Shear Scraper comes to mind, as does the Sorby.
I showed using a bull-nose scraper in the video because most turners already have one and this is a way for the tool to do double duty. I also have few dedicated and purpose built shear scrapers that I use and they work very well also. If you have any more questions, please do not hesitate to contact me. Take care and all the best to you and yours!