remember, no other audio output is required if your icecast server is running. the alsa output used in the link is just for fallback. if you do not want any output (audio) on the server itself, use only the shout output.
now, as it happened with me, may be you will encounter an error saying no audio device specified while playing music (i got this error with gmpc). if that’s the case, use mpc (cmd: mpc play).
depending on the buffer limit, the delay between the server and client might be upto 15 secs.
also, if you get “The file you requested could not be found” page on opening any streams, its true. you have fucked up somewhere, for instance, not keeping the user in the audio_output configuration as “source”, but “admin”, which was my admin user for icecast server :D.