llDialog and llListen

I have a script that uses dialogs, and of course that requires a listener to be running.

According to the wiki:
If the user selects "Ignore", the script will not receive an answer, so you can implement a timeout (recommended), or allow the dialog to be restartable from anywhere.

What timeout is this talking about, is it to have the script to stop listening by executing llListenRemove after a specific period of time?

Does this listening add to lag? I've not seen any clear examples of scripts using dialogboxes doing this.

I have noticed on my script that after touching the object and subsequently using the dialog boxes, the hourglass next to my pointer stays on. Is this related to that or something else?

Thanks for the opinions and help in advance!

Yep, the idea is to create a listen and set a timer event for every dialog you open up. Remove the listen after a command is received (or keep it open and reset the timer if it's a tiered dialog), or let the timer fire if someone just abandons it. The idea is that the listen is basically worhtless when the dialogs aren't active, so might as well kill it. Not a big lag reducer in isolation, but every bit helps.

Not sure about the hourglass thing.