^^
People pls don't mind if I disagree with you. I haven't reached a final and clear verdict in this case but here are my thoughts
Most of the verses quoted by you describe the reaction of 'kafirs' or 'rejectors' to Allah's signs manifested by His messengers. They said , 'It is clearly magic' etc. So they didn't accept the messengers but consider them as magicians / enchanters. The messengers were certainly not the magicians /enchanters /pretenders /deceivers. So these ayat certainly doesn't tell us about something like black/white or any other form of magic.
The verses of Al-Araf that discusses Moses as he appeared before the Pharoah. Magicians were gathered and Quran clearly tells us in 7:116 that the magicians 'enchanted the eyes' of the people and made them see something contrary to reality. The sort of magic mentioned here is 'trickry, enchanment of eyes, or may be hypnotisim'. This magic didn't change anything other than tricking the eyes of the people at large as jugglers do.
The Surah Falaq mentions 'the women who blow on knots'. I believe this is about those who, through their vicious acts, try to break the bonds (of relationship/frienship) out of jealousy. etc. but I will still investigate the background of this verse and other verses regarding magic.