I've test driven a car with no IACV. had no p/s or a/c or anyof that jazz. It won't die, but it would come close to it. Made it a little bit of a pain to drive.
Good thing I didn't buy it. The engine ended up dieing because of oil starvation issues in a few months.
Seems like it was a pretty popular thing for kids to do for a while, and their engines all died within a few months.
general consensus amongst those kids "KA's suck and they blow up all of the time"
consensus amongst those that think things through, The oil pressure drops too low when the rpms fall too far below idle. Since the engine would almost stall before recovering, the bearings would wearout from lack of oil. Who knows the amount of wear at the cams considering it takes a considerable amount of pressure to get the oil to, and through the head to begin with. So that extra metal flakes in the oil just sped the process of killing the engine.

So, either find a nifty spot for the IACV or, set the idle considerably high so that when it does drop, it isn't dropping below 500rpms