Hey Deling! Yeah, they're replaceable! Find them here. The loops included on the 120mm skins though are 95mm and 85mm wide.
Hey Jeff! Tough to say for sure if they're compatible or not (we don't carry OMG) but if the spring cartridge is compatible with the Olympus rods then yes you'd need the tool to install them.
Hey Dan! Tough to say for sure without having the ski here, but I'd say there's a really good chance the 92mm will work as the Radical brakes are usually sized very conservatively so they tend to have extra wiggle room. When in doubt, go for 100mm though!
It's hard to state just how good these are without getting overly personal. Let's just say that the global quality of life index probably has a direct correlation with the amount of people in any given location wearing these things.
Hey Dan! Looks like you have the first gen Radical which used a brake attachment system very similar to the Dynafit Vertical. We occasionally get the Vertical Brake Retainers in here but we are out at the moment so the only way to get that retainer would be to order a complete brake which includes the brake assembly, the retainer, and two new lateral adjustment springs which you could discard during installation.