Having read this thread, I was a bit 0.o about psychic self defense. I asked my guides and they said they allowed/encouraged/wanted me to go about the white light self defense so I can learn to use my intention/will to disallow or allow what I want to contact with. It's a novice class, basically, about intention and attraction. It's not the protection that really matters. I resonate with that advice: until I am at a higher level, this is what's useful to me.
Go with what's good for you. If something goes right, great; if it screws up, you'll know. What other people say are just suggestions; you know that.