I'm not familiar with FRAPS, so I can't say what exact settings you need; but I know that most recording programs have trial limits to the length of recordings unless you purchase the program. That might be the causeo f the stoppage.

As for audio issues, they likely have to do with your capture settings. Make sure that the program is set to record audio from your microphone as well as the game. These settings can depend on your operating system as well, and there are usually tutorials to be found online for this.

I have used similar programs (namely Bandicam) in order to capture gameplay footage, and haven't found any problems with the program once I got it set up properly.