Focus with a .6x wide adapter?
 

This might seem like kinda a stupid question. If you can't zoom in to focus with a .6x adapter on the lens. How do you set focus given the viewfinder on the XL2 is not that great. Do you just eyeball it and pray?

The depth of field is so vast with a main Canon XL zoom lens set at the widest setting plus a .6X or .7X screwed on the front, that in most cases you should be able to move in fairly close to an object that fills the frame, manually focus (or autofocus and then switch it off) so that it can be locked in that focal distance for most of your shooting.

It's not that bad. I've done it a bunch.

It's worth a few hassles to have the wider view than the 0.7x model.