Carl - never tried the cooler, but the tank vent should take care of expansion of fuel in the tank. The temperature of the return line will cool the fuel before it gets back to the tank.
Often, a relatively easy way to dump the fuel into the top of the tank is to remove one of the screws holding the tank sending unit, bore a hole, through the screw, sweat in a piece of copper pipe, and use this as a spot for the return.
Jon.
