@magpiemischief you raised lots of points in your post.
Lots of people 'dabble' in lots of religions and belief systems.
Many Pagans follow their own path because there is no doctrine and no 'wrong' way to be Pagan.
Personally I don't need a god to police me, I'm responsible for my own actions (see Rule of Three/Rede), I'm not a sheep that follows blindly. The answers I seek are all in me. I don't do the right thing through fear of hell and damnation I do it because it's the right thing to do.
Any individual in a position of power, say for instance a vicar/Catholic Priest/ pastor can abuse that power....it happens in all belief systems/religions.
Why do you think the craft remains hidden/ secretive? You seem to think it's because it's bad. It's not. It's hidden to protect those involved.
Wicca it's self is indeed relatively new but witchcraft isn't. As I said in a pp not all witches are Wiccan and Paganism predates Christianity. Wicca (to me) draws on the old to make it compatible with the new (modern life).
As a pp said, the Rede and Rule of Three could be followed by everyone regardless of their beliefs and the world would be a better place for it.