it doesnt cost money or time to set up a IRC channel.

so why not simply set up a gateway channel
webchat.freenode.net/?channels=#cryptoideanoob
for instance which is the unmoderated noob general chatter.

and then just by changing the hashtag you can instantly make new channels.
webchat.freenode.net/?channels=#cryptoideaintermed - moderated
webchat.freenode.net/?channels=#cryptoideaadvanced - moderated and invite only

if small groups want to form private chats they can set up their own private chats
webchat.freenode.net/?channels=#cryptoidea1
webchat.freenode.net/?channels=#cryptoidea2
.....
webchat.freenode.net/?channels=#cryptoidea1000

it aint rocket science.. the hardest part is thinking up good channel names