Ignorance.
There is a superstition that carrying an acorn can give you long life, which started with the Druids.
Moon Day (compare with Sunday).
None of them, God created Sunday. The ancient Romans, who were pagans, included a Day of the Sun in their week, the origin of 'Sunday'.
No.
20%
In the Kiswahili language of African origin, "Jumapili" has the meaning of "Sunday."
i think psalms are chanted.
The superstition surrounding walking under a ladder is believed to have originated from ancient Egypt, where the triangle shape formed by a ladder leaning against a wall was seen as a symbol of the "holy trinity" and walking through it was considered disrespectful to the gods. This belief was later adopted by other cultures and evolved into a superstition associated with bad luck.
Yes
it depends what the superstition is, superstition itself is a feeling, something of the mind.
If you can find a company which offers such services on a Sunday, yes. There's no law against it that I can find.