You asked about thoughts on Black magic. This question gets asked a lot.
^ this will explain some of it
^ this will explain some more
For my personal opinion, I believe that calling it black or white magic is an over simplification of what magic is. Magic is colorless and the judgments attached to it are generally based in the one judging it. Some see all magic as bad and evil, therefore they call it black. Others see magic in a myriad of colors: white, green, brown, etc.
I am willing, and have on occasion, to curse or hex if I feel the need is there for such action. I have done this as protection or as a defense in situations I was a part of. In the life that we all live, situations arise in which a person is required to defend themselves and actions taken in self defense are not see as evil if they are done in moderation and with in the 'acceptable' areas of the law and popular moral belief. There are times this is taken to excess and those people are punished for such actions. In the world of magic one is not punished by courts of law but by the 'laws' of the universe. I have had consequences for my actions I did not perceive at the time I cast the spell and I have learned from those consequences in my own way. I have also experienced consequences for my acts of healing and protection with magic.
If you are going to work magic you must, in my opinion, be ready and willing to deal with all the consequences that come from it. All action has consequence. Non-action has consequence. If you are willing to face the consequences and not try to nullify them by more magic you will do well in this area. If you expect to never suffer again, I'm sorry you are on the wrong path.
Blessings, I hope this has helped you