I'm a very poor fighter pilot ,but even I know that missles are realy well balanced as it is. If the speeds are increased so much it will afect the game in a realy nasty way. They are simply too , no TOO , powerfull if those speeds are reached.
For the mines. The mine is a double edjed sword. So if the speed is increased to 200 , it is by far more possible to die from your own mines much more often then your oponent.