funny question, the cooler should be able to handle the temperature, but whether your cpu is stable at 1.3 does not depend on the temperature alone. if your chip needs more than 1.3V, then a cooler upgrade is not much use....
No..
A cooler does not bring much stability. If a CPU is overclocked. You have to buy a very good air cooler or cash cooler. You can overclock well with these.