It doesn't keep intake temps down. The EGR keeps combustion chamber temps down. While the actual temperature of the exhaust gases is very hot, the gases themselves are inert and do not burn on the ignition cycle of the engine. They take up space in the cylinder, and keep the air/fuel mix from burning hot enough to form oxides of nitrogen (which induces smog formation).
You could run your car without the EGR, but you would need to plug the hole in your rear exhaust manifold and install a "spoof" sensor or have the PCM reprogrammed so as not to set a Check Engine light. My car ran fine without one, but in the course of some troubleshooting we decided to reinstall it. Ultimately, the EGR systems on our cars are electronic and meter the exhaust gas very well. They aren't like the old mechanical EGRs of the 70s and 80s that robbed a motor of horsepower. Plus, if you leave it on, you're being a little more environmentally-conscious
EDIT: Here is a helpful explanation of an EGR valve