New to video work owners will complain. But that's normal to see overnight encoding runs.

About the audio video sync. If Nero doesn't offer a correction factor (I don't use Nero) I do have a method I use to correct this. I use VIRTUAL DUB to adjust this. I am not offering to teach the use of this free software or how to find it with google.com but note that it is possible and easy (for me) to correct such a sync issue.

If you paid for Nero, then call it in for a fix or ask for a refund since it's defective.

Bob