You have two problems with Fraps: Fraps may be too expensive for you, or it's only for windows operators. I've found an alternative to fraps on mac. By the way, I have two computers. one is windows, one is mac. :p Open Quicktime player, click file. It should say "New Screen Recording" click that. A record button will appear, with some options. We don't want the recordings spamming our desktop, so we're gonna have to make a new folder. Drag your recordings into that file.
I'm using it, but I'm finding a faster one. The QuickTime decreases my FPS heavily. (Macbook Pro, 13-inch, retina, late 2013)
Yes. Turn up the volume on the recording bar. Or you could use the separate audio program and fuse your computer's audio with your voice :P You could go to frapsformac.com and download their program. :P There's a separate audio recorder on Quicktime. Use that or click new screen recording, and turn the volume up! :D