Agreed on the Nicklist deal. I can understand how it may adversly effect poorly written scripts that use $comchan without checking ($me ison $chan) or whatever. I'm certain additional properties can be added or these identifiers can be adjusted to work properly around a populated nicklest of a parted channel.
I personally believe the visible nicklist should have little effect on script identifiers, and the user should be able to modify the nicklist at will... removing and adding entries, manually sorting it by friends or idle time or however they choose.