Due to the fact that during hand mixing of the dough there is a possibility that the ingredients, especially the yeast won't be uniformly dispursed throughout the dough mass. This is the reason why we like to suspend the compressed yeast in the water prior to adding it to the dough. In the case of ADY, it has to be pre-hydrated in water at 100F before addition, but once it has been hydrated, you can safely add it to the regular dough water for addition. In the case of IDY, while it doesn't need to be pre-hydrated when a mechanical mixer is used, when hand mixing, it is suggested that it first be pre-hydrated in 95F water, and then added to the regular dough water for addition.
Folding the dough is indeed the same as kneeding it, but in this application we are only folding/kneading it a few times, not for several minutes as many typically do.
When forming the dough piece into a pizza skin, we begin opening the dough ball from the center out, without ever touching the outer edge of the dough piece. This provides for a light, very porous rim to the baked crust. In some cases we will use a rolling pin to pin out the dough ball to only about 2/3 of the desired diameter, and then complete the opening process by hand stretching. This process also results in a decent raised edge. The main difference between mechanical gluten development and biochemical gluten development is that biochemical gluten development, when taken at the right time gives you full gluten development without any toughness or memory in the dough, while a dough that is mechanically mixed to full gluten development will be tough and rubbery. There is nothing to fear when hand mixing or kneading and then giving the dough time to ferment for biochemical gluten development as this will not result in excessive gluten development, but do keep in mind that the time needed for complete biochemical gluten development may be a little shorter when a significant amount of kneading has already been done to the dough. I hope I have answered your questions, please feel free to ask if you should have any more questions.
Tom Lehmann/The Dough Doctor