re: Taliban's atrocities -
Again, I'm telling you, I know lots of Shia families. Not just in America, but also Pakistan, and in other countries as well. No one prays on coals. This might be something from a certain village, that's something separate. But its not part of their ritual that everyone does.
Matham is something different - but I've also never seen matham tied in with namaz, nor have heard of it.
Maybe people who are practicing shias here can confirm what the reality is. Unless you are shia, and this is a practice in your family?