I thought I should chime in on this discussion on a number of points. FYI, I worked on creating the Diamond Feng Shui course, am the editor of Marie's newsletters, and have been studying with her quite intensely for the past 2-1/2 years.
Let's start with the reference to Black Hat feng shui. Marie's course is not black hat. The similarity is that both use the Space Feng Shui bagua which includes the meanings for each compass direction like Family for East and Fatherhood for Northwest. In Black Hat no compass is used and the bagua is simply placed over the house or room according to the front door. In Marie's system a compass is always used to determine where these energies are located, and they are arranged according to the ancient systems. There are other differences as well but that is the most defining.
Regarding Temple and Empty Lines: on page 66 of the manual it does say "The worst directions are Temple Lines and the Empty Lines between the 24 Feng Shui Mountains (you will explore this further in Level Three)." The reference to Level Three is not about the Lines but rather to the mention of the 24 Mountains. Thanks for bringing this up. We will clarify the text in the next printing.
On the science and spirituality of Diamond Feng Shui: Marie's inclusion of spiritual energies in her feng shui system is one of the reasons she is a Master. To become one you must add to the information currently available, taking it to another level in some way. Marie does this in a variety of ways including enhancing your personal energy field with the Tubes of Light meditation (very, very powerful - I do this myself two times daily and expand it to include the other individuals in my family, our family as a whole, and our home and property). Other enhancements are her color energies for the 24 facets of life and her system for using hexagrams.
Regarding "fear level energy" and music: The manual says "This level is associated with thrillers, hard rock, soft pornography, and images of violence." I think it would work as well if the reference to hard rock was removed. "Hard rock" can mean something different to everyone. The main idea is that soft porn and violence typify the level, so any music incorporating these things would qualify. Remember that she does not say you cannot expose youself to these things (watching television would be quite difficult to do if that was the case) but that if these are the majority of your exposure on a daily basis then "fear level" is where you're at. Notice that in the "opening level" she says you appreciate a variety of music.
As a side note to the music thing, for myself, the chi level of the environment makes a big difference in the energy level of music I can tolerate. A hot, sunny Minnesota summer day is perfect for cranking Van Halen or the Dead (I'm giving away my age here - LOL) but I definitely cannot tolerate that music in the cold, close winter.
And last but not least, as Marie herself told me quite some time ago on the question of "who to believe," you just have to choose. Educate yourself, try things and see if they work (as Marie herself continues to do to this day), and then go with the system that works for you. Trying to pick and choose little pieces or strategies from different masters and systems will only confuse and frustrate you. Trust me, I know, because I was the same way. I have stacks of books and DVDs on Feng Shui and much of the information is conflicting. I have chosen to work only with Marie's system, including Dowsing and Inner Diamond, and it has been wonderfully beneficial in all areas of my life. If I had to give up every book and access to information I have and could only be left with one I would keep my Diamond Feng Shui learnings.
Let me know if you have any questions.