Nick length can't exceed 16 chars, yet lernid lets you go more

NIce catch, Coalwater. It may be possible to tell gtk through the data/ui xml files what the maximum length is, then someone wouldn't even be able to type more than 16 characters.

Hint: the max_length property, the file is ConnectDialog.ui, and the gtkEntry object is called password. (The first mention of "password" is in the label for that field).

Whoops. That was for the password, and you were talking about the Nick. Are they both limited to 16 characters?

The nick gtkEntry object is called "nick_textentry"

Keep in mind, the nick length will be different for each network. If you type '/version' (you might need to do '/raw version' or '/quote version'), you will see something like this:

SAFELIST ELIST=U CASEMAPPING=rfc1459 CHARSET=ascii NICKLEN=16 CHANNELLEN=50 TOPICLEN=390 ETRACE CPRIVMSG CNOTICE DEAF=D MONITOR=100 are supported by this server

The 'NICKLEN=16' is what sets the max nick length. This information is usually sent along with the MOTD when you connect to the network.

The password does not have this same length restriction.

Is there an existing module that can send queries to the server?

I don't remember seeing anything but but irc and private (nickserv)
messages being sent, but I may simply not have noticed yet. Of course
Lernid is using empathy to communicate with the irc server.

As to what the pertinent python module is, I would suggest lernid/IrcBackend.py