I was reading up somewhere that there is a real problem with some sheetrock that came out of China spreading mold/mildew/allergens.. other than that I don't know.
I hung sheetrock quite a bit last summer.. Putting it in the ceiling is the most challenging, I can do just about any other areas by myself, though.
Our house has a special green insulation.. we have recycled phonebooks in our walls.. they collect the old phone books, chop them up into bits and then they get sprayed into the wall cavities.. it sticks on its own, so they must make some kind of paste out of it? It was pretty cool to watch.
Our old house had virtually no insulation and the outer walls were pretty cold, too.. The house was like 50 years old, and the fiberglass insulation that had been stapled into the walls had with time just fallen down into the bottoms of the wall cavities (I guess it is pretty common for old homes).. I got some foam outlet cover things and installed those myself which cut down the draft blowing out of the outlets around the house.. (take the outlet plate covers off, put on the foam ones, and screw the covers back on) those are pretty cheap.. I think there is also some kind of insulation foam that can fill in wall cavities without removing the sheetrock (just drill a hole in it and spray it in really), but I don't know anything about its greenness..