Aloha Marit,
There is a lot of different teaching on the est direction to sleep. In the Essentials part of the course Marie gives you the Diamond Feng Shui perspective on it.
As for magnets, same thing. I have a doctor/Spring Forest qigong student friend of mine that says the benefit of sleeping in a magnet-lined bed stops after an hour and then hinders the body the more time after that. Is it accurate? I don't know. Like Check it out and see what is true for you, your system, and situation.
Much Love, Shawn