No. Satan, or the Devil, has absolutely no place in Wicca or Witchcraft. The worship
of Satan is the practice of profaning Christian symbolism and is thus a Christian heresy, rather than a Pagan religion. The Goddess and God of the Witches are in no way
connected to Satanic practices. Satan, or the Devil, is a Christian creation and they are more than welcome to keep him.

This is another baseless superstition and Witches wear clothing and robes of every color. Black is the combination of all colors and all vibrational rates of light on the material plane. It is known that black is a very good conductor of energy, therefore wearing black simply helps Witches absorb natural energy to increase the power of their thought forms. 

This practice has its history in a couple of different things, none of which have anything to do with evil... In the old world, especially within the Celtic tribes, the day followed an entirely different schedule than it does in modern times. The new day for them actually began at sunset. This is also why most observances of holidays were celebrated on the evening before the actual calendar day. The second reason is that survival had an entirely different meaning during those times. Almost without exception, everyone spent their daylight hours tending the crops, their herds, or engaged in their trade. All daylight hours were vitally important simply for survival reasons.

OK, so that takes care of why we observed our rites at night during ancient times, and many of the reasons are the same in today's times. For one, most of us are busy working all day earning a living, so the evening is the only time we have to seek spiritual communion. Secondly, Wicca and Witchcraft are still largely misunderstood religions and we are still persecuted for our beliefs. Another reason which is important for me, and possibly for others as well is that I feel a special closeness to the Goddess and God at night. Yes I can, and do, enjoy the mountains and meadows during the daylight, or a sunrise and sunset, but I am truly more aware of the heavens and the great expanse of the Universe at night, so it just makes sense for me.