I suspect that as many Anglicans as Orthodox find heavy metal music meaningful; perhaps more.
The issue of whether a particular variant of music is less Christian than another, or worse still, whether any variant of music has the potential to lead us away from Christ himself, is an interesting one. Having read the thread, I can see why you feel so strongly about the effects of heavy metal, W. No doubt it does have the potential you say it has, but I am not sure that potential is strong enough to affect our brothers and sisters in TAW.
After that I can only speak from my own experience, which is very limited indeed. As you know, W, I have a variant of post traumatic stress disorder, which means I have to be very careful what images and sounds I let into my head; they have the potential to make me very unwell if they are too violent or graphic. I can't watch disasters, or murder depictions or even the news if it gets too bad. I can read outlines of the news, but I can't let the images in. Other people can watch the same things with no bad effects whatever.
Some people are more sensitive to this kind of imagery than others. I have not listened to anything like heavy metal for many years, but I suspect it would make me unwell. I tend to be careful about music, but if given a choice (as when I am alone in the house) I prefer silence. Silence is safe, and allows me to draw closer to God.
In general, if we are serious about our relationship with God, then nothing we do will be thoughtless; the music we choose to listen to, the films we watch, the people we associate with; all will be chosen to reflect our faith. The points you raise are good ones, and worth bearing in mind, therefore.