Tamal has his reasons for taking his vengeance out on Miria's father. Let's just say Miria's father wasn't as wonderful a person as she believed, but he was a very, very good father. Miria only ever saw the good in her father, so even now, all these years later, she has a difficult time grasping the idea that he was a totally different and very ugly person to Tamal. Does that justify Tamal killing the rest of her family, though? No. Despite Tamal's reasons behind his actions, he's not any better of a person. Miria struggles with the black-and-white of what is wrong with people, and everything in between.

Oh, I love complicated stuff like that, mwahaha.

As for the religion.... I kinda like the idea that the jinn have their own religion that is separate from what the humans believe. It gives that element of mystery to their culture that makes them all the more interesting :) That's just my opinion of it, anyway.