Yep, Don't worry Jojo, there have never been any recorded cases of a CD-Writer being damaged by overburning
People just want to cover their backs. They could also say that over burning a CD *may* cause the CD Writer to attack you in your sleep, but it doesn't make it any more likely in happening [:p]
The only thing you have to worry about is making sure the CD doesn't have corrupt data at the end of the session. Nero CD Speed is probably the best CD quality checker you can use to test the burn. You can find it in the Nero Tool Kit.
The only other option to over burning is make the file smaller, you can trim out credits, ot re-encode it, or cut into half and put it on two CDs (though that one isn't the greatest choice for space management!)