to the intercooler. The vacuum leak created will be too large to allow start up. Fab up something like ZEngineer suggests. Don't drive the car that way of course, just idle testing.
You can start the car fine without the radiator. Obviously don't let it run for more than 10 minutes or so, otherwise it will start to overheat.
No exhaust is not a problem. The car will just be LOUD. :-)