Should I pre-boil then rinse chicken bones before making stock?
This sounds counterproductive. Making stock means that you let the boiling water leach nutrients, flavors, and other stuff from the bones. Then you remove the solid parts (bones, scum) and are left with the gelatine and flavors dissolved in the water. 

Now, if you preboil the bones and throw away the water, you throw away all the flavor which has been leached in this boil. Sure, some flavor will remain in the bones for prolonged boiling, but it will be less, and it won't be the same flavor (some tastes will cook out sooner than others). In short, the process which creates scum is the same which creates stock; you can't have one without the other. 

In your home kitchen, you can mostly live with cloudy stock if you don't feel like skimming. Clear stock is more desirable, but you can keep that for special occasions. And exactly these occasions are the one when you want the most flavor, so don't compromise by preboiling.