I haven't found how to delete it no, maybe you need to wipe the custom settings?
Here's an idea for you Canon:
Make the WB button on the 1d X access the "Sample and register WB" directly. Or even better, have it register WB directly when you push the WB button, that would not be too much to ask and save 50 pushes of a button.
As for the AF registered point, I'm not really sure what you mean, When I choose one pont, push the shutter half way and push the multicontroller it jumps between the registered and the center point, but it never blinks and show if I haven't selected it..