Is there a clearances diagram on the back of the stove? If yes, what is the make and model of the stove? The current hearth is too shallow for the stove. There is nothing really protecting the floor in front of the stove. That carpet is a bandaid. If this is not a UL listed stove it requires 36" clearances in all directions and 16" of hearth in front of the glass of the stove. The brick wall (if real brick) will reduce the clearance down to 24" but the stove looks installed much closer than that. As for the pipe, maybe one of the older installers here will remember. It is older Amerivent. I thought the old 6FB was triple wall, but could be wrong and defer to the experts on this topic.