besides /ctcp #channel VERSION and /ctcp #channel PING and the /ctcp $nick version and ping commands, are there any other ways of finding mIRC users?

The channel was made to be accessible only by a specific client and to keep mIRC users (except for operators) out, but I think some people have modified their client to reflect the typical access client version and block ping. The time function is equipped within the access client.

You want people to help you evade a rule? No thanks, go find another message board pls..

Lemmie guess, this is CR (Conference Room) with +j on... short answer: it is impossible to stop people getting around this unless teh java client has heaps of stuff extra coded into it.
Long answer: Any proficient scripter can write a proxy in mirc script, and connect to it. From there, they can control entirely all of the output/input to mirc, and halt all sorts of /ctcp replys etc. There's no way to detect people who do this, if they do it well.