This is not uncommon.  Lots of people have removed their rear heaters for more storage space, especially out here in California where it's rarely if ever needed.  

Regarding using it for "extra cooling", this generally over-kill.  The radiator on vanagons is massive and with the fan does a fantastic job of keeping the motor cool.   If you actually needed the extra cooling you could always use the front heater , but then I suppose it's blowing in your face...  Personally I wouldn't kick the heater for extra cooling on until I heard the radiator fan kick up to high speed.  Just MHO, btw you'll know the difference between the fan being on low and high when it happens which is exceedingly rare.  I only know because for a while my fan resistor had shorted and it'd only go on high... 

-Jon