My single story house is cinder block on slab and the oil furnace duct goes straight up off the heat exchanger into the attic (so does the exhaust stack) and there it branches off in ducts for all the rooms. This furnace area (small utility room) has major heat loss and I want to insulate the attic with roll fiberglass thoroughly around where the duct and stack comes through the ceiling. Do I need a special type to be against these hot metal objects? Also my kitchen attic could use another layer but there are lots of wires from the ceiling lights (not recessed) and wall outlets. To simplify a thankless job is it safe to just lay the fiberglass roll insulation over the wires? Lastly, I do have one recessed light in the living room directly over the hearth. I would like to put insulation over that and tight up against the masonry chimney (with ss liner) as this is another area of heat loss. What type do I need there? I intentionally neglected these 3 areas when I added roll insulation a few years back for fear of fire danger. But I'm sick of the heat loss and really need to do something about it, just want to be sure I don't cause a fire and end up burning the house down! Thanks in advance.