Fast Axle shaft replacement
 

I broke a CVD at a comp, and had to spend way too long trying to replace it, since I had to split the housing to remove it. Is it necessary to run the inner E-clip? This way, if a shaft breaks, I could just slide it out for replacement. I would imagine grinding a slot for an e-clip on the stub shaft for inside the knuckle, would keep it from moving.

You shouldn't have to use the clip, the bearings in the knuckle alone will keep it from trying to slide out.