YouTube audio player with a shortcode.
Tools -> AudioTube to adjust the plugin options
Use the shortcode
[audiotube id="PWJmwi1qJdQ"] to play a video as an audio file. Use only the video id grabbed from the URL, i.e., "http://www.youtube.com/watch?v=PWJmwi1qJdQ?hl=en". Start after "?v=" and ends before "?hl=en".
No. You can just copy/paste the inc/shortcode.php into your functions.php, following the instructions in this file.