And thats why the cooper has a faster 0-60 and top speed?

With a relitively small increase such as the one from the superchip there shouldnt be an issue with overheating. There will be marginally more wear on parts like the clutch but thats not likely to effect you too much. As this chips not in the form of bluefin you wouldnt just be able to return it to normal if you took it in to the garage so your warranty would be void which is a bummer

Emissions wont really be effected and fuel economy could increase due to more driveability from a better spread of torque etc but obviously if you push the car economy will drop