Redlining really does reduce the life of your engine. Peak power tails off before the redline so all you are doing is making a lot of noise.
Thinking about it though the noise is fun
Modern rev limiters stop sudden damage to an engine and if you get the engine balanced your red line will be higher.
Here was a once in a lifetime engine killing opportunity which taught me something interesting. In an Astra 1.4 increase your speed, drop down to 3rd where the revs will go beyond the rev limiter preset effectively disabling the rev limiter. It was an interesting exercise to note that the Astra rev limiter stops an engine reaching the rev limit but cannot reduce an engine to below that limit!
Dont try this at home though unless you really do want to blow up your engine.