I kerf about 80% of my logs with a circular saw before splitting, taking the time and read the pattern of the bark/grain then lay out the cut line with keel. Being form a bow desert, I try to save/get as many staves as possible from each log and kerfing them minimizes the amount of side tear-out. I get 1-2 extra staves out of each log. As for safety, use a good saw (preferably a worm drive), sharp blade, have the log held securely, use both hands, and stand to the side while cutting. Do not try and make turns with the blade in the log, stop the blade, raise it up and make several new cuts with the toe of the plate on the log. I spray my blade with WD-40 after each kerf to minimize sap build up and extend the blade live.