Is the why in why are you sad? the beginning of a sentence

Yes. Any sentence can begin with any word. Just avoid using "because" as the beginning of a sentence. Though it can be used.

Yes. Try to avoid the word "because" . The first word of a sentence is always the first.

•as parts of ceremonies and often to ask for peace and blessings from evil. • late at night to entertain themselves or foreign visitors at the camp. • on long journeys through the arizona desert, to keep their energy and minds boosted. • during the long winter nights, when they were cold and the land was not suitable for farming.

Where's the excerpt? also i think the answer is the last one