Lucid dreaming is just dreaming conciously. It isn't witchcraft.
Also Hps Maxine was incredibly busy. She only wrote the essentials. Not everything is in the JoS. You have to apply the basics and the advanced principles on the JoS then reach a level where you can start learning from your Gaurdian Demon and learning stuff that isn't on the JoS.
You will also get to know secret information that can't be released to the public because of the enemy but that is only if the Gods decide that you are trust worthy of their secrets.