CPU "damage" is really when the CPU wears away - too high of a voltage causes accelerated chip degradation, causing it to require more and more voltage to run stably over time.
It is recommend you keep it within stock to prevent any noticeable degradation. VID: 0.800V-1.375V
I'd say keep it under 1.4v for regular use and ~1.4 or slightly above for benchmarking only.
No, my CPU is fine it's at 1.33.
If you read my question you'd see I was talking about the DRAM Voltage.