well easy way to determine if your alternator is stuffed get the car started, remove the earth off the battery if the car remains idling then alternator is fine.
your pads are always meant to be in contact with the rotor. So by your desciption your rotors are warped.
I find one you warp a rotor, get them machines, they seem to rewarp after a while.
i reckon over 140 is possible if im willing to take it right to the limiter. I havent bounced my car off it before, dont wanna try.
its not a skyline tho, its an FTO, thats why i reckon its so slow, cause of the tall second gear! ehehehehe
probably a collapsed cat. You notice any loss in power?
also dont know if it true or not when your car is warm, put your hand 5-10 cms aways from exhuast if its stinking hot your cat is buggered.