The main reason for re-applying is to avoid trapping bubbles when re-attaching a HSF. As long as the CPU did not detach from the HSF, air should not be getting in-between and you should be ok.
As far as damaging the CPU goes, you would probably crack your motherboard before you manage to damage the CPU since pressure you apply to the HSF is transferred to the IHS which spreads pressure across a large chunk of the LGA socket which is backed by the CPU socket retention plate on the back-side which prevents flex around the immediate CPU area.
Temperature-wise, you can expect 80-85C with Prime95 on stock HSF. If you want to run CPU-intensive stuff like that continuously, you should consider upgrading to some sort of half-decent aftermarket cooling. With the 212EVO, you could expect 65-75C.