omg you people. Look, mIRC is NOT a file sharing program nor is IRC a file trading medium. IRC was designed to be a highly open chat medium, and for its purpose, it does what it does VERY well.
Surely it has advanced in the past few years, but at heart it is meant for chat. If you think you could compare IRC to any ways of getting pirated software like a file sharing medium, you need to grow up and see what IRC is for.
Yes, there are people out there who use functions provided by IRC to transmit files, but it's just a chat medium.
IRC was not meant to have 'buddy lists' or anything of that sort, as IRC is an open and very widespread medium. You can setup IRC servers for anything, there's no central 'service' to it. Therefore, unless all of your friends connect to the same server, you won't be seeing them 'online'.
However, I will let you know of the wonderful /notify function of mIRC, and you're welcome to build off of that into a dialog script to make your own 'buddy list'.