I looked into this. Actually the calling of StartAudio twice is not a bug, I give the user the option to call it via the audio dropdown or by typing in the name. So the same method is called but with different parameters. I did however notice that I duplicated the ID's of some actions and that was causing the wrong method to be called. I fixed that and updates the plugin at https://github.com/koza/appMobiC2Plugin.
As for deploying on the PC, in order for the appMobi plugin to work, you need to export your game for appMobi. In case you are not familiar with appMobi, not only does our build system allow you to deploy to mobile devices like IOS, Android, Kindle Fire and Nook. But also for the web to Facebook, The Chrome Store, Mozilla Store, HostMobi or to your own server.
The easiest way to test your game is to export your game from C2 and run them in our XDK.
I updated the example .capx file to illustrate how to play a sound effect. You can download it at https://www.dropbox.com/s/lsuzlgr8s4yl7ye/audioDemo.capx. Check it out in C2, then export to appMobi and select "Phone Browser" instead of "DirectCanvas". Then you can test that bundle in our XDK.
I hope that all makes sense. If you need assistance with our XDK or build system, feel free to PM me, I'll be happy to help.