Re, heat control...

 >> It now won't turn off, so we had to shut the heater vents for the
entire trip home.  Any simple fixes?  No, of course not.  The valve is
stuck open, and can only be gotten to by removing the dash.  I
probably won't tackle this job myself, and so will pay considerably
for it. <<

  This is pretty easy to diagnose by yourself.

  You might have a kinked cable, happened to me way back when, and is
fairly easy to access by yourself from underneath the dash.  Remove
the cover that's in front of the shifter (fingers into the
grilles...pull) for access.

 The heater valve itself is underneath the bus- drop the spare tire
and it's easy to spot.  Make sure it's closed all the way.  If it is
and you still have heat, and assuming the cable's adjusted properly
and not kinked it'll need to be replaced.

Geo/ATL