I would get rid of the grate around the fire. My understanding of vision quests is that they take place in the wilderness where you would not find such things. I would also change the ground tex to be more dirt and sand, then I would scatter a couple rocks and twigs around. You could also do with a little vegetation. I would also make the astral texture more solid, yet transparent. By that I mean to eliminate the particles. BTW I like your concept and think it is the best one so far.