Regarding keep it simple and nature... I wouldnt expect many people to know this but most seeds have simple needs in order to sprout, and some seeds will not sprout at all unless they meet the criteria.

Some seeds need to be digested in order to germinate by an animal. The animal eats the plant with the seeds, and poops them out. hehe. The seed coat is degraded and allows for germination to take place. Scuffing the seeds is in place of nature and will allow your seeds to germinate, or in the case of marijuana it will allow them to germinate faster and more efficiently/effectively. It may not be neccessary, but is something that takes place in nature.
Seeds also need to burn off the dormant enzymes that keep them from sprouting in the middle of the winter, thats why we need to keep them warm, and in a dark place to simulate being under ground.

Aside from the scuffing, i have also herd of people taking an sharp knife and scuffing at the seeds shell where the sprout comes out of, anything that you do to the seed is fine as long as you dont pierce through it and damage the embryo.