It should replace all of the characters he listed. Char's #0-31 are all control characters which can't be used in filenames.
Of course, although they're not expressly forbidden in any IRC RFC, it's pretty stupid to allow them in a channel name since they're all non-printable and so may appear as spaces or not appear at all in many fonts. Not to mention the problems arising from a channel name having characters which most IRC clients interpret as text-formatting.
Yes, but when I open a channel with the Logging options in mIRC, mIRC replace the illegal char with a _ or `. So, in IRCNET this char are used in some standard channels, and for this reason I think that mIRC should replace those char with a _ or `.