I haven't yet used Icecast with this service and centovacast (am considering this as the Shoutcast directory may be becoming less relevant compared to such things as Tunein and Reciva portals due to the sheer amount of online stations, and all of these portals have their own commercial agenda), but I have got some experimental setups using Icecast.
if the DJ/presenter has got the wrong spelling of the mountpoint but entered a valid source password, a new mountpoint may be created with the wrong name (I am not sure if the Centovacast guards against this)
If that happens, this may result in your live DJ's stream consuming bandwidth (as there is still data traffic from the studio to the server), listeners still getting the auto DJ (as Icecast doesn't see the live stream) until the stream is connected to the correct mountpoint.
There also a chance your DJ ends up streaming to the incorrect mountpoint as well as the correct one (most software can send more than one stream); and is unaware of this; as monitoring from the listener end is not so easy for a DJ (especially if they are beat mixing) due to encoding delay and they may already be stressed/confused by the earlier problems. On most DJ software the streaming control window is set up then closed as it would otherwise take up space that can be used for other stuff.
For live shows it is worth at the very least having someone else around as well as the DJ who can access the server control panel (I think those are accessible for both shoutcast and icecast) and is contactable in real time and can also contact the DJ (if they are not in the same location). What the Taiko crew from Scotland always did for their live shows (as they mixed vinyl) was dedicate an entire computer with a pro audio soundcard for streaming and comms (via IRC chat).
Nothing wrong with computer based DJ equipment - I use it myself when I get the time as I don't have room for vinyl decks and the genres I prefer these days are no longer released on vinyl; but one person running the DJ software, streaming and chat etc (and often twitter, whatsapp and all sorts else) on their laptop isn't good practice. it might just about work but is putting all your eggs in one basket.
Computers and audio equipment are way cheaper nowadays and in shared houses or family houses there is usually more than one computer around anyway....