I lived in SE Alaska (Ketchikan, actually) back in the '70's. We used
an old refrigerator to smoke salmon. We put a hot plate in the bottom
of the fridge and put a cookie sheet filled with green alder chips on
the hot plate. Worked great! Some friends of mine did build an
"outhouse style" smoke house, similar to what you describe, but alas,
through putting too much wood on the fire and subsequent inattention
during the smoking process, they let the fire get too hot, so
everything went up in smoke - smokehouse and all! Moral of story -
don't drink too much beer while smoking fish.

As far as drying herbs goes, I now live in Colorado where our summers
are hot and dry most of the time. I just hang herbs upside down in
small bunches inside paper bags in a clean dry place. The paper bags
keep dust and light away from the herbs, so they stay green after they
dry. When dry, I package them in glass jars or plastic baggies and
then put them in the deep freeze for at least 48 hours to kill any
lingering "critters." After that, I just store them on a shelf in the
pantry.