I Googled for the problem, and that page came up. Can as focus here? There's some bug where rebinding these keys breaks them, or at least doesn't inform you of the change. I'll have to try. In any case, it's a problem. I fixed it by setting Sheath back to R. I really don't get how people use like WASD and all the keys in between while also using the mouse. I have to take my hands off the mouse to do stuff, which then cripples me from other actions. Seriously, if anyone could find an explanation of how you manage it, I'd be grateful.
The only keys that you need to hit often which are away from wasd are the menu keys which can also be accessed with the slightly slower use of the tab key. And them being menu keys means that it doesn't matter when you take your fingers off the movement keys.
Unless you have small hands which make it hard to reach "r" and such.
for me reaching r doesn't require any movement of the wrist, just a small reach of the finger. I can comfortably reach everything to the left of and including the i k and m keys. without taking my middle finger off of w.