Maybe not what you wanted, but it's a start:
Add this line in nick list popups (alt-p alt-v 4)
$address($$1,5):echo -a $address($$1,5)
Now you can just rightclick on a nick and have his complete nick!ident@address. Rightclick works not only in nicklist but also in the channel window itself, for any nicks that are not in text. There's an option where you need to press shift to have the hand appear over nicks. See Options (alt-o) -> Other -> Keys... -> Hotlinks only when shift key pressed
