Bread – the purpose of nutmeg in apple zucchini bread

Salt (Sodium chloride) is salt. As a topping, flakes are commonly used purely for presentation purposes only. The taste is the same, but gets more intense as the salt particles get finer, so use less if the salt is in powder form

As an ingredient, use any form you are happy with, and is economical to use. Once salt is dissolved into water it will be identical to any other form of salt

For health reasons, finely powdered salt is preferable as much less is required to impart a salty taste

In addition to allowing fermentation to begin before the addition of fermentation inhibiting other ingredients, as @J.A.I.L. said in his answer, according to Bread Secrets, after explaining the benefits to flavor of a long, slow fermentation:

A quick, warm fermentation will allow time for the yeast to produce enough carbon dioxide to raise the dough, but not enough time for the enzymes to work or for the development of the other flavour compounds. If we ferment our dough for too long, however, the gluten becomes too weak to hold the shape of the loaf. So artisan bakers generally use a preferment (pre-ferment, not prefer-ment!) as part of their dough. This allows the bread to gain flavour from the longer fermentation, but still maintain a strong gluten network for a good rise.