3: what consequences could there be to using certain magic, since you told me it can "boomerang" back This is the only time magick ever really gets tricky in my opinion. A lot of people only do the "light and love" magic because they dontwant to orknow how to prevent boomerangs. Curses, blood magic, or love spells tend to have consequences if you do them wrong (regardless if you believe in the 3 fold law).
Do a curse wrong, and it will reflect off the person and hit you right back (i have heard you can prevent this by using certain things in your spells. Like a dead bee. but I haven't tried that myself.)
Blood magic can be dangerous for a few reasons. One you should never cut yourself ever and if you do that can be serious. Get infected. It's not pretty. And should you do it, it tends to really drain a person of energy
A way around that is mainly for women, but just use your period blood. It is super strong because it came from a sacred place on the human body, you didnt have to harm yourself to take it - it just be flowin. and its the most powerful blood there is.
If you are a man and cant do that method, you can use like the left over blood from your steak dinner, or chicken livers (drain it for the blood and then deep fry them livers, magic and dinner. done)