I will put it simply the stock radiator has plastic end tanks. Coming from the BMW world I have first hand experience with Plastic end tanks detonating at speed. They can and do crack or come apart Plastic was never meant to be a pressure radiator material. While it might work for some to me its a ticking time bomb.
Hence I got an aluminum radiator early one. Once can argue they have not need it temp wise. When your going 75 mph and the end tank decides to let go you will be very surprised.

As far as the intercooler goes ya you can get by with a stock intercooler if your not running autocross and track or canyons or doing lots of pulls. Otherwise its a known weak link as well.