Software for getting Mic into Shadowplay videos?

My computer isn't quite beefy enough to handle recording or streaming all the games I like to play unless I do it through Shadowplay, which is unfortunately still very limited, so I'm looking for a few, basic programs that will patch up the missing features until NVidia puts them in themselves.  Also, I'm looking for both Windows 8 and Linux compatible solutions because I imagine NVidia will get up to speed on Linux by the time Steam Machines arrive, but who knows when Shadowplay will be all together.

  1. Some kind of audio recording software.  Just strictly mic to any audio format of at least mp3 quality.  Compression isn't an issue because of 2:
  2. Some kind of really basic A/V software that just cuts and splices audio and video files, and maybe has some simple transitions and captions.  I've found tons of free software that does that plus 100 other things that make absolutely no sense to me, but is not very intuitive because all the buttons for all the fancy crap gets in the way of me just doing 20 minutes of video to file 1, 15 minutes of video to file 2, and some voice over the last 15 minutes to file 3.
  3. Anything that can take the output of Shadowplay and stream it more-or-less live.  I have basically zero expectations that something like this even exists, but if it does then I'd like to know.

I'm also aware of an alternative plan where I just get a program that feeds the Mic back to audio out in real time, since it seems that Shadowplay listens to any/all audio out and records that, but I feel like the potential for feedback there makes it a really bad idea.

Tangential Question: I know lots of people with high-end AMD cards also use NVidia cards to just do PhysX.  Have any of you guys played around with Shadowplay and does it work with this setup?

EDIT: 2 days after this was posted, mic capture was patched into Shadowplay.  I'll re-post with a new question later.

1) Audacity will do it, it's only for windows though http://audacity.sourceforge.net/

For the other two i'm not very sure.