Your 5ghz could be reduce in lifespan of your cpu processor chip. OCUK had advise everyones to use 4.6Ghz no more than that.
Yes.
seldom use a computer more than 2 years anyhow.
did run a i7 920 at 1.45vcore for 2 years without any issues.
Lifespan for new tech is like a year with the current cpu business.